USH1540H - Electrical components formed of lanthanide chalcogenides and method of preparation - Google Patents
Electrical components formed of lanthanide chalcogenides and method of preparation Download PDFInfo
- Publication number
- USH1540H USH1540H US08/283,478 US28347894A USH1540H US H1540 H USH1540 H US H1540H US 28347894 A US28347894 A US 28347894A US H1540 H USH1540 H US H1540H
- Authority
- US
- United States
- Prior art keywords
- lanthanide
- silver
- chalcogenides
- temperature
- mixed metal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 229910052747 lanthanoid Inorganic materials 0.000 title abstract description 34
- -1 lanthanide chalcogenides Chemical class 0.000 title abstract description 25
- 238000000034 method Methods 0.000 title description 5
- 238000002360 preparation method Methods 0.000 title description 4
- 229910052751 metal Inorganic materials 0.000 claims abstract description 50
- 239000002184 metal Substances 0.000 claims abstract description 50
- 150000004770 chalcogenides Chemical class 0.000 claims abstract description 37
- 239000000463 material Substances 0.000 claims description 24
- 230000004044 response Effects 0.000 claims description 3
- 239000000126 substance Substances 0.000 claims description 3
- 229910052709 silver Inorganic materials 0.000 abstract description 30
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 abstract description 26
- 229910052802 copper Inorganic materials 0.000 abstract description 25
- 239000004332 silver Substances 0.000 abstract description 25
- 239000000843 powder Substances 0.000 abstract description 17
- 239000011669 selenium Substances 0.000 abstract description 16
- BUGBHKTXTAQXES-UHFFFAOYSA-N Selenium Chemical compound [Se] BUGBHKTXTAQXES-UHFFFAOYSA-N 0.000 abstract description 12
- 229910052711 selenium Inorganic materials 0.000 abstract description 12
- 239000004065 semiconductor Substances 0.000 abstract description 10
- 229910052717 sulfur Inorganic materials 0.000 abstract description 10
- 229910052714 tellurium Inorganic materials 0.000 abstract description 10
- 150000002602 lanthanoids Chemical class 0.000 abstract description 9
- 229910052737 gold Inorganic materials 0.000 abstract description 8
- 239000004020 conductor Substances 0.000 abstract description 6
- 239000003989 dielectric material Substances 0.000 abstract description 5
- 229910052746 lanthanum Inorganic materials 0.000 abstract description 2
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 abstract description 2
- 230000004927 fusion Effects 0.000 abstract 1
- 239000010949 copper Substances 0.000 description 24
- 239000000203 mixture Substances 0.000 description 19
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 16
- 239000010453 quartz Substances 0.000 description 15
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 14
- 239000013078 crystal Substances 0.000 description 14
- 229910052691 Erbium Inorganic materials 0.000 description 13
- 238000000634 powder X-ray diffraction Methods 0.000 description 12
- 229910052692 Dysprosium Inorganic materials 0.000 description 11
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 11
- 239000008188 pellet Substances 0.000 description 11
- 229910052688 Gadolinium Inorganic materials 0.000 description 10
- 239000010931 gold Substances 0.000 description 10
- RKTYLMNFRDHKIL-UHFFFAOYSA-N copper;5,10,15,20-tetraphenylporphyrin-22,24-diide Chemical compound [Cu+2].C1=CC(C(=C2C=CC([N-]2)=C(C=2C=CC=CC=2)C=2C=CC(N=2)=C(C=2C=CC=CC=2)C2=CC=C3[N-]2)C=2C=CC=CC=2)=NC1=C3C1=CC=CC=C1 RKTYLMNFRDHKIL-UHFFFAOYSA-N 0.000 description 9
- KBQHZAAAGSGFKK-UHFFFAOYSA-N dysprosium atom Chemical compound [Dy] KBQHZAAAGSGFKK-UHFFFAOYSA-N 0.000 description 9
- PORWMNRCUJJQNO-UHFFFAOYSA-N tellurium atom Chemical compound [Te] PORWMNRCUJJQNO-UHFFFAOYSA-N 0.000 description 9
- UYAHIZSMUZPPFV-UHFFFAOYSA-N erbium Chemical compound [Er] UYAHIZSMUZPPFV-UHFFFAOYSA-N 0.000 description 8
- 239000011593 sulfur Substances 0.000 description 8
- 229910052693 Europium Inorganic materials 0.000 description 7
- 150000001875 compounds Chemical class 0.000 description 7
- UIWYJDYFSGRHKR-UHFFFAOYSA-N gadolinium atom Chemical compound [Gd] UIWYJDYFSGRHKR-UHFFFAOYSA-N 0.000 description 7
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 7
- 238000005259 measurement Methods 0.000 description 7
- 239000012299 nitrogen atmosphere Substances 0.000 description 5
- UVLRAQIGJZOHKK-UHFFFAOYSA-N silver dysprosium(3+) selenium(2-) Chemical compound [Se-2].[Se-2].[Dy+3].[Ag+] UVLRAQIGJZOHKK-UHFFFAOYSA-N 0.000 description 5
- BTGZYWWSOPEHMM-UHFFFAOYSA-N [O].[Cu].[Y].[Ba] Chemical compound [O].[Cu].[Y].[Ba] BTGZYWWSOPEHMM-UHFFFAOYSA-N 0.000 description 4
- 238000001816 cooling Methods 0.000 description 4
- OGPBJKLSAFTDLK-UHFFFAOYSA-N europium atom Chemical compound [Eu] OGPBJKLSAFTDLK-UHFFFAOYSA-N 0.000 description 4
- 150000004771 selenides Chemical class 0.000 description 4
- 229910021521 yttrium barium copper oxide Inorganic materials 0.000 description 4
- 238000002847 impedance measurement Methods 0.000 description 3
- KPKXBNQQQBSLQO-UHFFFAOYSA-N silver erbium(3+) selenium(2-) Chemical compound [Se-2].[Se-2].[Er+3].[Ag+] KPKXBNQQQBSLQO-UHFFFAOYSA-N 0.000 description 3
- 230000007704 transition Effects 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- JBRZTFJDHDCESZ-UHFFFAOYSA-N AsGa Chemical compound [As]#[Ga] JBRZTFJDHDCESZ-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- GYHNNYVSQQEPJS-UHFFFAOYSA-N Gallium Chemical compound [Ga] GYHNNYVSQQEPJS-UHFFFAOYSA-N 0.000 description 2
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 2
- 229910052765 Lutetium Inorganic materials 0.000 description 2
- 229910052779 Neodymium Inorganic materials 0.000 description 2
- 229910052777 Praseodymium Inorganic materials 0.000 description 2
- 229910052773 Promethium Inorganic materials 0.000 description 2
- 229910052772 Samarium Inorganic materials 0.000 description 2
- 239000005864 Sulphur Substances 0.000 description 2
- 229910052771 Terbium Inorganic materials 0.000 description 2
- 229910052769 Ytterbium Inorganic materials 0.000 description 2
- GRVIANAASNJXGO-UHFFFAOYSA-N [S--].[S--].[Cu++].[Dy+3] Chemical compound [S--].[S--].[Cu++].[Dy+3] GRVIANAASNJXGO-UHFFFAOYSA-N 0.000 description 2
- NIDPHGBZWGSXIM-UHFFFAOYSA-N [S--].[S--].[Cu++].[Er+3] Chemical compound [S--].[S--].[Cu++].[Er+3] NIDPHGBZWGSXIM-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000003990 capacitor Substances 0.000 description 2
- 229910052798 chalcogen Inorganic materials 0.000 description 2
- 150000001787 chalcogens Chemical class 0.000 description 2
- 230000001419 dependent effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- JPIIVHIVGGOMMV-UHFFFAOYSA-N ditellurium Chemical compound [Te]=[Te] JPIIVHIVGGOMMV-UHFFFAOYSA-N 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- ZUNLRMXHVJDCME-UHFFFAOYSA-N erbium Chemical compound [Er].[Er] ZUNLRMXHVJDCME-UHFFFAOYSA-N 0.000 description 2
- JLKGLVHGFTWOSK-UHFFFAOYSA-N erbium silver Chemical compound [Ag].[Er] JLKGLVHGFTWOSK-UHFFFAOYSA-N 0.000 description 2
- 229910052733 gallium Inorganic materials 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000001453 impedance spectrum Methods 0.000 description 2
- 229910052738 indium Inorganic materials 0.000 description 2
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 description 2
- 229910010272 inorganic material Inorganic materials 0.000 description 2
- 239000012212 insulator Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 229910052976 metal sulfide Inorganic materials 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 239000000615 nonconductor Substances 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- VQMWBBYLQSCNPO-UHFFFAOYSA-N promethium atom Chemical compound [Pm] VQMWBBYLQSCNPO-UHFFFAOYSA-N 0.000 description 2
- 230000002285 radioactive effect Effects 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- XSOKHXFFCGXDJZ-UHFFFAOYSA-N telluride(2-) Chemical compound [Te-2] XSOKHXFFCGXDJZ-UHFFFAOYSA-N 0.000 description 2
- 150000004772 tellurides Chemical class 0.000 description 2
- 229910052716 thallium Inorganic materials 0.000 description 2
- BKVIYDNLLOSFOA-UHFFFAOYSA-N thallium Chemical compound [Tl] BKVIYDNLLOSFOA-UHFFFAOYSA-N 0.000 description 2
- 230000032258 transport Effects 0.000 description 2
- 229910052684 Cerium Inorganic materials 0.000 description 1
- RWSOTUBLDIXVET-UHFFFAOYSA-N Dihydrogen sulfide Chemical compound S RWSOTUBLDIXVET-UHFFFAOYSA-N 0.000 description 1
- 229910052689 Holmium Inorganic materials 0.000 description 1
- 229910052775 Thulium Inorganic materials 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- MUTIUPSQRZCMCX-UHFFFAOYSA-N [Cu++].[Se--].[Se--].[Dy+3] Chemical compound [Cu++].[Se--].[Se--].[Dy+3] MUTIUPSQRZCMCX-UHFFFAOYSA-N 0.000 description 1
- DETGUAVLVXQDRX-UHFFFAOYSA-N [S-2].[S-2].[Dy+3].[Ag+] Chemical compound [S-2].[S-2].[Dy+3].[Ag+] DETGUAVLVXQDRX-UHFFFAOYSA-N 0.000 description 1
- FPQYAAHJYYOALI-UHFFFAOYSA-N [Se-2].[Se-2].[La+3].[Ag+] Chemical compound [Se-2].[Se-2].[La+3].[Ag+] FPQYAAHJYYOALI-UHFFFAOYSA-N 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 239000012300 argon atmosphere Substances 0.000 description 1
- 239000012298 atmosphere Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- ZMIGMASIKSOYAM-UHFFFAOYSA-N cerium Chemical compound [Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce] ZMIGMASIKSOYAM-UHFFFAOYSA-N 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000004590 computer program Methods 0.000 description 1
- MAASVPSFVCRLTM-UHFFFAOYSA-N copper gadolinium(3+) disulfide Chemical compound [S--].[S--].[Cu++].[Gd+3] MAASVPSFVCRLTM-UHFFFAOYSA-N 0.000 description 1
- 239000002178 crystalline material Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000002050 diffraction method Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- AISZYAUSYCMRPR-UHFFFAOYSA-N dysprosium(3+) gold(3+) selenium(2-) Chemical compound [Se-2].[Se-2].[Dy+3].[Au+3] AISZYAUSYCMRPR-UHFFFAOYSA-N 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- KJZYNXUDTRRSPN-UHFFFAOYSA-N holmium atom Chemical compound [Ho] KJZYNXUDTRRSPN-UHFFFAOYSA-N 0.000 description 1
- 229910000037 hydrogen sulfide Inorganic materials 0.000 description 1
- 238000003331 infrared imaging Methods 0.000 description 1
- 150000002484 inorganic compounds Chemical class 0.000 description 1
- 239000011147 inorganic material Substances 0.000 description 1
- 230000037427 ion transport Effects 0.000 description 1
- OHSVLFRHMCKCQY-UHFFFAOYSA-N lutetium atom Chemical compound [Lu] OHSVLFRHMCKCQY-UHFFFAOYSA-N 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000005693 optoelectronics Effects 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- PUDIUYLPXJFUGB-UHFFFAOYSA-N praseodymium atom Chemical compound [Pr] PUDIUYLPXJFUGB-UHFFFAOYSA-N 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 150000002910 rare earth metals Chemical class 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- KZUNJOHGWZRPMI-UHFFFAOYSA-N samarium atom Chemical compound [Sm] KZUNJOHGWZRPMI-UHFFFAOYSA-N 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- SPVXKVOXSXTJOY-UHFFFAOYSA-N selane Chemical compound [SeH2] SPVXKVOXSXTJOY-UHFFFAOYSA-N 0.000 description 1
- 229910000058 selane Inorganic materials 0.000 description 1
- 229910052814 silicon oxide Inorganic materials 0.000 description 1
- 150000003378 silver Chemical class 0.000 description 1
- 239000010944 silver (metal) Substances 0.000 description 1
- YXQJVZXPEYYOCY-UHFFFAOYSA-N silver erbium(3+) disulfide Chemical compound [S-2].[S-2].[Er+3].[Ag+] YXQJVZXPEYYOCY-UHFFFAOYSA-N 0.000 description 1
- RATNQEPTJINPCO-UHFFFAOYSA-N silver gadolinium(3+) disulfide Chemical compound [S-2].[S-2].[Gd+3].[Ag+] RATNQEPTJINPCO-UHFFFAOYSA-N 0.000 description 1
- 238000010583 slow cooling Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 150000004763 sulfides Chemical class 0.000 description 1
- 229910000059 tellane Inorganic materials 0.000 description 1
- GZCRRIHWUXGPOV-UHFFFAOYSA-N terbium atom Chemical compound [Tb] GZCRRIHWUXGPOV-UHFFFAOYSA-N 0.000 description 1
- 235000012431 wafers Nutrition 0.000 description 1
- 238000002424 x-ray crystallography Methods 0.000 description 1
- NAWDYIZEMPQZHO-UHFFFAOYSA-N ytterbium Chemical compound [Yb] NAWDYIZEMPQZHO-UHFFFAOYSA-N 0.000 description 1
- 229910052727 yttrium Inorganic materials 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B19/00—Selenium; Tellurium; Compounds thereof
- C01B19/001—Preparation involving a liquid-liquid extraction, an adsorption or an ion-exchange
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
- H01B1/06—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
- H01B1/06—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances
- H01B1/10—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances sulfides
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
- H01B3/02—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of inorganic substances
- H01B3/025—Other inorganic material
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/0248—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies
- H01L31/0256—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by the material
- H01L31/0264—Inorganic materials
- H01L31/032—Inorganic materials including, apart from doping materials or other impurities, only compounds not provided for in groups H01L31/0272 - H01L31/0312
- H01L31/0324—Inorganic materials including, apart from doping materials or other impurities, only compounds not provided for in groups H01L31/0272 - H01L31/0312 comprising only AIVBVI or AIIBIVCVI chalcogenide compounds, e.g. Pb Sn Te
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
- C01P2002/77—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by unit-cell parameters, atom positions or structure diagrams
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/40—Electric properties
Definitions
- the present invention relates generally to the preparation of electrical components formed of certain lanthanide chalcogenide compounds and, in particular, to the preparation of electrical components formed of silver and copper lanthanide chalcogenides.
- inorganic materials such as silicon and gallium arsenide in the formation of electronic circuits and microcircuits (e.g. thermal on off switch) for controlling the flow of current at varying temperatures is well known.
- U.S. Pat. No. 2,814,004 to Goodman discloses an electrically semiconductive object comprising a body of semiconductive material which includes a chemical compound having a formula MNX 2 where M represents one of the elements copper and silver, N represents one of the elements aluminum, gallium, indium and thallium, and X represents one of the elements sulphur, selenium and tellurium.
- Goodman also discloses a method of producing an electrically semiconductive object by melting together in an inert atmosphere at high temperatures quantities of a first group of elements copper and silver, at least one of a second group of elements aluminum, gallium, indium and thallium and at least one of a third group of elements sulphur, selenium and tellurium in atomic proportions determined by the formula MNX 2 and then cooling the melt to form the semiconductor object upon solidification.
- the electrical components and the method of preparing the same as disclosed by Goodman are limited to semiconductors, that is transistor type devices such as a crystal diode.
- Japanese Patent No. 60-191,006 discloses a method for preparing lanthanide sulfides, selenides and tellurides by heating a mixture of a lanthanide alkoxide with the appropriate hydrogen sulfide, hydrogen selenide or hydrogen telluride.
- the resultant metal sulphide, selenide and telluride can be used to prepare, for example, optical disc.
- the disclosure of Japanese Patent No. 60-191,006, however, does not suggest that the resultant metal sulphide, selenide and telluride have any electrical properties and thus are useful as semiconductors such as diodes or other electronic devices.
- U.S. Pat. No. 4,061,505 to Hampl discloses certain N-type thermoelectric compositions based on a rare-earth metal selected from gadolium and erbium and a chalcogen selected from selenium and tellurium.
- the thermoelectric compositions of U.S. Pat. No. 4,061,505 may be used as thermoelectric legs in thermoelectric generators.
- a family of electrical components which can function as insulators, dielectrics, semiconductors or metallic-like conductors, in the form of a series of non-metallic inorganic compounds, namely, silver and copper lanthanide chalcogenides, having varying electrical properties over a wide temperature range of about -50° C. to temperatures in excess of +100° C.
- the complex metal (copper and silver) lanthanide chalcogenides of the present invention are in the form or sulfides, selenides and tellurides.
- the silver and copper lanthanide chalcogenides of the invention may be used as electronic switching devices, diodes, photovoltaic cells and as infrared detector materials for infrared imaging and infrared spectrophotometers. Since the electrical properties of the silver and copper lanthanide chalcogenides of the invention are temperature dependent, these materials may also be used as temperature dependent electronic switches for controlling modern automobile equipment which may overheat such as engines, air conditioners and pollution equipment. Further useful applications for the silver and copper lanthanide chalcogenides of the invention include controlling rocket engines and controlling lighting systems for spacecraft and satellites which are exposed to hot and cold temperatures.
- the silver and copper lanthanide chalcogenides of the invention are prepared by a repeated melting cooling process over a time period of at least a week to form an electronically active, single phase, crystalline material.
- the metal lanthanide sulfides are pure dielectrics and may be used in charge storage devices such as capacitors, the metal lanthanide selenides have Schottky type semiconductor properties and the metal lanthanide tellurides are ceramics with metallic-like conductor properties.
- these compounds may be used as thermally reversible switches which turn on current when there is a temperature increase and which turn off current when there is a temperature decrease.
- FIG. 1 is a perspective view illustrating the crystal structure of the trigonal phase of the mixed metal chalcogenide AgErTe 2 of the present invention
- FIG. 2 is a perspective view illustrating the crystal structure of the tetragonal phase of the mixed metal chalcogenide AgDySe 2 of the present invention
- FIG. 3 is a perspective view illustrating the crystal structure of the orthorhombic phase of the mixed metal chalcogenide AgErSe 2 of the present invention
- FIG. 4 is a perspective view illustrating the crystal structure of the orthorhombic phase of the mixed metal chalcogenide CuDyS 2 of the present invention.
- FIG. 5 is a graphical representation of the conductivity of the mixed metal chalcogenide AgErSe 2 as a function of temperature
- FIG. 6 is a graphical representation of the conductivity of the mixed metal chalcogenide AgErTe 2 as a function of temperature
- FIG. 7 is a graphical representation of the conductivity of the mixed metal chalcogenide AgDySe 2 as a function of the wavelength of incident light;
- FIG. 8 is a graphical representation of the X-Ray Powder Diffraction Pattern for the mixed metal chalcogenide AgErSe 2 ;
- FIG. 9 is an electrical schematic diagram of the mixed metal chalcogenides constituting the present invention.
- the mixed metal chalcogenides constituting the present invention include chemical compounds having the formula MLnX 2 , where M represents one of the elements copper, silver or gold (Cu, Ag, or Au); Ln represents any one of the 14 metals in the lanthanide family of elements in the periodic table, atomic numbers 58-71, with the exception of radioactive promethium, as follows: cerium, lanthanum, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium (Ce,La,Pr,Nd,Sm, Eu,Gd,Tb,Dy,Ho,Er,Tm, Yb and Lu); and X represents sulfur, selenium or tellurium (S, Se or Te) in the chalcogenide family of elements. Promethium (Pm) is excluded because its only known isotope
- the preferred compounds of the present invention are formed using the silver and copper lanthanide chalcogenides.
- the mixed metal chalcogenides constituting the invention and having the formula MLnX 2 exhibit electrical properties ranging from dielectrics to semiconductors to metallic conductors over a wide temperature range of -50° C. to in excess of 100° C.
- Dielectrics are generally embodied by those compounds which contain either silver or copper in combination with a lanthanide metal (e.g. europium, dysprosium, erbium, gadolinium) and sulfur having the formula MLnS 2 where M is Ag or Cu, and Ln is a lanthanide metal such as Eu, Dy, Er or Gd.
- a lanthanide metal e.g. europium, dysprosium, erbium, gadolinium
- sulfur having the formula MLnS 2 where M is Ag or Cu, and Ln is a lanthanide metal such as Eu, Dy, Er or Gd.
- Semiconductors are generally embodied by those compounds which contain either silver, or copper in combination with a lanthanide metal (e.g. europium, dysprosium, erbium, gadolinium) and selenium having the formula MLnSe 2 where M is Ag or Cu, and Ln is a lanthanide metal such as Eu, Dy, Er or Gd.
- a lanthanide metal e.g. europium, dysprosium, erbium, gadolinium
- selenium having the formula MLnSe 2 where M is Ag or Cu, and Ln is a lanthanide metal such as Eu, Dy, Er or Gd.
- Metallic conductors are generally embodied by those compounds which contain either silver or copper in combination with a lanthanide metal (e.g. europium, dysprosium, erbium, gadolinium) and tellurium of the formula MLnTe 2 where M is Ag or Cu, and Ln is a lanthanide metal such as Eu, Dy, Er or Gd.
- a lanthanide metal e.g. europium, dysprosium, erbium, gadolinium
- tellurium of the formula MLnTe 2 where M is Ag or Cu, and Ln is a lanthanide metal such as Eu, Dy, Er or Gd.
- the mixed metal chalcogenides of the invention are prepared according to a preferred embodiment by mixing the three basic materials in powder form, that is the metal, which may be silver or copper, the element from the lanthanide family which may be, for example, dysprosium or gadolinium, and the chalcogen which may be sulfur, selenium or tellurium in stoichiometric proportions in a molar ratio of about 1:1:2.
- the resulting mixture of these three basic elements is then slowly fused under vacuum by sealing the mixture in quartz tubes, evacuating the same, and slowly heating the mixture over an extended time period at an elevated temperature, for example, of 1150° C.
- the resulting product is cooled and may be analyzed during the cooling period by using X-ray powder diffraction to determine the crystal structure of the particular lanthanide chalcogenide compound.
- the pure crystallography phases of the lanthanide chalcogenide compounds can also be monitored by using x-ray crystallography.
- the mixed metal chalcogenides of the invention have a crystal structure which is trigonal, tetragonal, orthorhombic or octahedral.
- FIG. 1 illustrates the crystal structure of the trigonal phase of the mixed metal chalcogenide AgErTe 2
- FIG. 2 illustrates the crystal structure of the tetragonal phase of the mixed metal chalcogenide AgDySe 2
- FIG. 3 illustrates the crystal structure of the orthorhombic phase of the mixed metal chalcogenide AgErSe 2
- FIG. 4 illustrates the orthorhombic phase of the mixed metal chalcogenide CuDyS 2 .
- the mixed metal chalcogenides of the invention can be produced as thin wafers, pellets or crystals that conduct electricity above a specific transition temperature T c and are non-conductive below temperature T c .
- a current can be allowed to flow in an amplifier or signal generating circuit fabricated from the mixed metal chalcogenides of the invention when the material is warmed above T c , but the current can be stopped as soon as the temperature drops below T c .
- FIG. 5 illustrates the conductivity of AgErSe 2 as a function of temperature measured in degrees Kelvin
- FIG. 6 illustrates the conductivity of AgErTe 2 as a function of temperature. As is best illustrated in FIG.
- the mixed metal chalcogenide AgErTe 2 has an electron conductive temperature dependency that parallels the low temperature superconductivity of yttrium barium copper oxide.
- This mixed metal chalcogenides is, in turn, superconductive at higher temperatures (about 250° K.) than the temperature at which yttrium barium copper oxide becomes superconductive.
- the electrical components of the invention in the general class of silver, copper or gold lanthanide chalcogenides, can be formed into electronic components or used in electronic "microchip” devices in conjunction with electrically conducting metals (such as copper, silver or gold) and non-conductors (such as silicon oxide or aluminum oxide insulators).
- electrically conducting metals such as copper, silver or gold
- non-conductors such as silicon oxide or aluminum oxide insulators.
- the lanthanide chalcogenides hereof can be sputter-coated onto various substrates. The following are examples illustrating production of the mixed metal chalcogenides of the invention:
- a mixture was made of 108 grams of silver powder, 162.5 grams of dysprosium powder and 64 grams of powdered sulfur (1:1:2 molar ratio) under a nitrogen atmosphere in a glove box. About 3.0 grams of this mixture was placed in a 6 inch quartz tube which was evacuated and sealed under vacuum, using a high performance diffusion pump and a mercury manometer (vacuum was below 1 torr). The quartz tube was placed in a tubular furnace and was slowly heated to 1150° C. over a 5 day period. The mixture was held at 1150° C. for another 5 hours, then it was cooled to 700° C. over a week, and finally held at 650° to 700° C. for another 90 days. The quartz tube was then removed from the furnace and analyzed for purity using x-ray powder diffraction. The resultant material has a tetragonal form crystal structure.
- Copper Gadolinium Disulfide (CuGdS 2 ).
- a mixture of 63.5 grams of copper powder, 157.25 grams of gadolinium powder and 64 grams of sulfur powder were mixed under nitrogen in a glove bag. About 3.5 grams of this mixture was placed in a 6 inch quartz tube, which was then evacuated and sealed under vacuum. The tube was slowly heated to 1150° C. for a period of 7 days, and then the tube was held at this temperature for another 8 hours. The tube was then cooled to 700° C. slowly, over a week, and was then held at 650° C. to 700° C. for 45 days. Finally, the tube was cooled to room temperature and the powder was removed. The powder was analyzed via x-ray diffraction (XRD) until the monoclinic phase was obtained.
- XRD x-ray diffraction
- Copper Erbium Disulfide (CuErS 2 ).
- Copper, erbium, and sulfur powders were mixed in 1:1:2 molar ratios under a nitrogen atmosphere. About 3.5 grams of this mixture was placed in a quartz tube which was evacuated and sealed under vacuum. The tube was slowly heated to 1150° C. over a 3 day period, held at 1150° C. for 3 hours, cooled to 700° C. over a week and held at 650° C. to 700° C. for 4 months. During this period the material was analyzed by x-ray powder diffraction until the orthorhombic phase was obtained.
- Copper Dysprosium Disulfide (CuDyS 2 ).
- Copper, dysprosium, and sulfur powders were mixed in 1:1:2 molar ratios under a nitrogen atmosphere.
- About 3.5 grams of this mixture was placed in a quartz tube which was evacuated and sealed under vacuum. The tube was slowly heated to 1150° C. over a 3 day period, held at 1150"C. for 3 hours, cooled to 700° C. over a week and held at 650° C. to 700° C. for 3.5 months. During this period the material was analyzed by x-ray powder diffraction until the orthorhombic phase of FIG. 4 was obtained.
- AgErS 2 Silver Erbium Disulfide
- Silver, erbium, and sulfur powders were mixed in 1:1:2 molar ratios. About 3.0 grams of this mixture was placed in a quartz tube which, after evacuation, was sealed. The tube was slowly heated to 1150° C. over 10 days, held at 1150° C. for 6 hours, cooled to 700° C. over a week and held at 650° C. to 700° C. for 5 weeks. After this time the pure tetragonal phase was obtained, as indicated by x-ray powder diffraction.
- Silver Gadolinium Disulfide (AgGdS 2 ).
- FIG. 8 illustrates the x-ray powder diffraction pattern for AgGdS 2 .
- Silver Dysprosium Diselenide (AgDySe 2 ).
- Silver, erbium, and selenium powder were mixed in 1:1:2 molar ratio and placed in quartz tubes.
- the tubes were evacuated and sealed.
- the tubes were then heated over 3 days to 1150° C., held at this temperature for 2-3 hours and cooled over 2 days to 700° C., at which temperature the tubes were maintained for 3-4 months. During this period the material was periodically analyzed by x-ray powder diffraction until only the single tetragonal phase was obtained.
- Silver, erbium, and selenium powder were mixed in 1:1:2 molar ratio under a nitrogen atmosphere. About 3.5 grams of this mixture were placed in a quartz tube which was evacuated and sealed under vacuum. The tube was slowly heated to 1150° C. over a 3 day period, held at this temperature for 3 hours, cooled to 700° C. over a week and held at 650° C. to 700° C. for 4 months. During the 4 month period the material was analyzed until the single orthorhombic phase of FIG. 3 was obtained.
- Silver Dysprosium Diselenide (AgDySe 2 ).
- Silver Erbium Ditelluride (AgErTe 2 ).
- Silver, erbium, tellurium powders were mixed in a 1:1:2 molar ratio, placed in quartz tubes, evacuated and sealed, heated over 3 days to 1150° C. and maintained at this temperature for 2-3 hours. The tubes were then slowly cooled to 600° C. and maintained at this temperature for a time period of 2-3 months. During this 2-3 month time period the material was periodically analyzed by x-ray powder diffraction until only a single trigonal phase, FIG. 1, was present.
- a pellet was formed by uniaxial compression of 150 mg of silver lanthanum diselenide powder in a 0.125 inch diameter die at 3000 lbs. of force. Electrodes were applied as a gold powder on the front and back surfaces or the pellet, and the powder was pressed into a gold foil at 2000 lbs. The pellets were mounted in a spring loaded measurement cell and enclosed in a vessel of dry argon gas to keep out moisture. This entire apparatus, with the pellet specimens, was placed inside an environmental chamber where temperatures could be varied from -50° C. to +100° C.
- Tables I, II, III and IV disclose the bond lengths and angles/atomic positions (X, Y, Z coordinates) for the single phase crystal structures respectively of FIGS. 1, 2, 3 and 4. It should be understood that any conventional and well known X-ray crystallography computer software program may be used to calculate the bond length and angles of the crystal structures illustrated in FIGS. 1, 2, 3 and 4.
- the pattern calculated for the trigonal space group P3m 1 , FIG. 1, is as follows:
- the pattern calculated for the tetragonal space group I4 1 md, FIG. 2, is as follows:
- the pattern calculated for the orthorhombic space group P2 1 2 1 2 1 is as follows:
- the pattern calculated for the orthorhombic space group P2 1 2 1 2 1 , FIG. 4, is as follows:
- the capacitor C g is the geometric capacitance ( ⁇ 10 pF)
- C dl is the double layer capacitance ( ⁇ 10 pF)
- R i is the ionic transport resistance
- R e is the electronic transport resistance.
- Copper Erbium Disulfide (CuErS 21 ).
- This material was highly resistive.
- the DC resistivity tended to decrease with temperature. At low temperatures, the material was insulating. This was reflected in impedance spectra data for temperatures between -50° C. and +22° C., which depicted a virtually pure dielectric behavior of CuErS 2 at these low temperatures. At a temperature of approximately 100° C., the DC conductivity was found to be 8 ⁇ 10 -5 S/cm. Low frequency deviations became more severe at lower temperatures, as was found in data taken at 79° C. This scatter is coupled with the fact that the signal to noise ratio was low at the low frequency measurements.
- the impedance spectra was generally complex indicating a semiconductor Schottky contact was formed between the AgErSe 2 pellet and the Au electrodes.
- Silver Erbium Ditelluride (AgErTe 2 ).
- Copper Dysprosium Disulfide (CuDyS 2 ).
- Silver Dysprosium Diselenide (AgDySe 2 ), orthorombic phase.
- FIG. 7 there is shown a graph which illustrates the current flow in a nanoamps of a Silver Dysprosium Diselenide (AgDySe 2 ) pellet as a function of the wavelength of incident light in nanometers.
- Silver Dysprosium Diselenide can be used in the fabrication of photo-electric devices such as optical couplers, optoisolators, light detectors and like optoelectronic devices.
- the mixed metal chalcogenides having the chemical formula AuDySe 2 Gold Dysprosium Diselenide
- the mixed metal chalcogenides having the chemical formula CuDySe 2 (Copper Dysprosium Diselenide) exhibit similar electrical properties, that is each of these mixed metal chalcogenides generates a light induced photocurrent in response incident on the material.
- the invention provides a series of mixed metal chalcogenides in the form of a family of silver, copper and gold lanthanide chalcogenides having highly useful electrical characteristics over a wide range of temperatures.
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Abstract
Mixed metal chalcogenides formed of lanthanide chalcogenides having the formula MLnX2 where M is selected from the group consisting of Ag, Cu and Au; Ln is one of the elements of the lanthanide family other than Pm and X is selected from the group consisting of S, Se and Te and having electrical properties that range from dielectrics to semiconductors to metallic conductors in a temperature range from -50° C. to in excess of +100° C. The lanthanide chalcogenides can be prepared by slow fusion of the basic elements such as silver, lanthanum and selenium, in substantially stoichiometric properties, in powder form under an extended time period at elevated temperature, e.g. 650° C. to 700° C.
Description
This application is a continuation-in-part of U.S. patent application Ser. No. 08/086,981, filed June 30, 1993.
1. Field of the Invention
The present invention relates generally to the preparation of electrical components formed of certain lanthanide chalcogenide compounds and, in particular, to the preparation of electrical components formed of silver and copper lanthanide chalcogenides.
2. Description of the Prior Art
The use of inorganic materials such as silicon and gallium arsenide in the formation of electronic circuits and microcircuits (e.g. thermal on off switch) for controlling the flow of current at varying temperatures is well known.
U.S. Pat. No. 2,814,004 to Goodman discloses an electrically semiconductive object comprising a body of semiconductive material which includes a chemical compound having a formula MNX2 where M represents one of the elements copper and silver, N represents one of the elements aluminum, gallium, indium and thallium, and X represents one of the elements sulphur, selenium and tellurium. Goodman also discloses a method of producing an electrically semiconductive object by melting together in an inert atmosphere at high temperatures quantities of a first group of elements copper and silver, at least one of a second group of elements aluminum, gallium, indium and thallium and at least one of a third group of elements sulphur, selenium and tellurium in atomic proportions determined by the formula MNX2 and then cooling the melt to form the semiconductor object upon solidification. The electrical components and the method of preparing the same as disclosed by Goodman are limited to semiconductors, that is transistor type devices such as a crystal diode.
Japanese Patent No. 60-191,006 discloses a method for preparing lanthanide sulfides, selenides and tellurides by heating a mixture of a lanthanide alkoxide with the appropriate hydrogen sulfide, hydrogen selenide or hydrogen telluride. The resultant metal sulphide, selenide and telluride can be used to prepare, for example, optical disc. The disclosure of Japanese Patent No. 60-191,006, however, does not suggest that the resultant metal sulphide, selenide and telluride have any electrical properties and thus are useful as semiconductors such as diodes or other electronic devices.
U.S. Pat. No. 4,061,505 to Hampl discloses certain N-type thermoelectric compositions based on a rare-earth metal selected from gadolium and erbium and a chalcogen selected from selenium and tellurium. The thermoelectric compositions of U.S. Pat. No. 4,061,505 may be used as thermoelectric legs in thermoelectric generators.
While the prior art discloses a very limited use of selenium or tellurium in the preparation of compositions which exhibit semiconductor characteristics, a detailed disclosure and analysis of the many useful electrical components which may be formed from certain lanthanide chalcogenide compounds is not found in the prior art.
According to the present invention, there is provided a family of electrical components which can function as insulators, dielectrics, semiconductors or metallic-like conductors, in the form of a series of non-metallic inorganic compounds, namely, silver and copper lanthanide chalcogenides, having varying electrical properties over a wide temperature range of about -50° C. to temperatures in excess of +100° C. The complex metal (copper and silver) lanthanide chalcogenides of the present invention are in the form or sulfides, selenides and tellurides. The silver and copper lanthanide chalcogenides of the invention may be used as electronic switching devices, diodes, photovoltaic cells and as infrared detector materials for infrared imaging and infrared spectrophotometers. Since the electrical properties of the silver and copper lanthanide chalcogenides of the invention are temperature dependent, these materials may also be used as temperature dependent electronic switches for controlling modern automobile equipment which may overheat such as engines, air conditioners and pollution equipment. Further useful applications for the silver and copper lanthanide chalcogenides of the invention include controlling rocket engines and controlling lighting systems for spacecraft and satellites which are exposed to hot and cold temperatures.
The silver and copper lanthanide chalcogenides of the invention are prepared by a repeated melting cooling process over a time period of at least a week to form an electronically active, single phase, crystalline material.
It has been found that the metal lanthanide sulfides are pure dielectrics and may be used in charge storage devices such as capacitors, the metal lanthanide selenides have Schottky type semiconductor properties and the metal lanthanide tellurides are ceramics with metallic-like conductor properties.
Additionally, it has been found that certain metal lanthanide chalcogenides/mixed metal chalcogenides have electron conductive temperature dependency that parallels the low temperature superconductivity of yttrium barium copper oxide. These mixed metal chalcogenides are, in turn, superconductive at higher temperatures than the temperature at which yttrium barium copper oxide becomes superconductive.
Accordingly, these compounds may be used as thermally reversible switches which turn on current when there is a temperature increase and which turn off current when there is a temperature decrease.
FIG. 1 is a perspective view illustrating the crystal structure of the trigonal phase of the mixed metal chalcogenide AgErTe2 of the present invention;
FIG. 2 is a perspective view illustrating the crystal structure of the tetragonal phase of the mixed metal chalcogenide AgDySe2 of the present invention;
FIG. 3 is a perspective view illustrating the crystal structure of the orthorhombic phase of the mixed metal chalcogenide AgErSe2 of the present invention;
FIG. 4 is a perspective view illustrating the crystal structure of the orthorhombic phase of the mixed metal chalcogenide CuDyS2 of the present invention;
FIG. 5 is a graphical representation of the conductivity of the mixed metal chalcogenide AgErSe2 as a function of temperature;
FIG. 6 is a graphical representation of the conductivity of the mixed metal chalcogenide AgErTe2 as a function of temperature;
FIG. 7 is a graphical representation of the conductivity of the mixed metal chalcogenide AgDySe2 as a function of the wavelength of incident light;
FIG. 8 is a graphical representation of the X-Ray Powder Diffraction Pattern for the mixed metal chalcogenide AgErSe2 ; and
FIG. 9 is an electrical schematic diagram of the mixed metal chalcogenides constituting the present invention;
The mixed metal chalcogenides constituting the present invention include chemical compounds having the formula MLnX2, where M represents one of the elements copper, silver or gold (Cu, Ag, or Au); Ln represents any one of the 14 metals in the lanthanide family of elements in the periodic table, atomic numbers 58-71, with the exception of radioactive promethium, as follows: cerium, lanthanum, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium (Ce,La,Pr,Nd,Sm, Eu,Gd,Tb,Dy,Ho,Er,Tm, Yb and Lu); and X represents sulfur, selenium or tellurium (S, Se or Te) in the chalcogenide family of elements. Promethium (Pm) is excluded because its only known isotope is radioactive and has a half life of less than 1 hour.
The preferred compounds of the present invention are formed using the silver and copper lanthanide chalcogenides.
The mixed metal chalcogenides constituting the invention and having the formula MLnX2 exhibit electrical properties ranging from dielectrics to semiconductors to metallic conductors over a wide temperature range of -50° C. to in excess of 100° C.
Dielectrics are generally embodied by those compounds which contain either silver or copper in combination with a lanthanide metal (e.g. europium, dysprosium, erbium, gadolinium) and sulfur having the formula MLnS2 where M is Ag or Cu, and Ln is a lanthanide metal such as Eu, Dy, Er or Gd.
Semiconductors are generally embodied by those compounds which contain either silver, or copper in combination with a lanthanide metal (e.g. europium, dysprosium, erbium, gadolinium) and selenium having the formula MLnSe2 where M is Ag or Cu, and Ln is a lanthanide metal such as Eu, Dy, Er or Gd.
Metallic conductors are generally embodied by those compounds which contain either silver or copper in combination with a lanthanide metal (e.g. europium, dysprosium, erbium, gadolinium) and tellurium of the formula MLnTe2 where M is Ag or Cu, and Ln is a lanthanide metal such as Eu, Dy, Er or Gd.
The mixed metal chalcogenides of the invention are prepared according to a preferred embodiment by mixing the three basic materials in powder form, that is the metal, which may be silver or copper, the element from the lanthanide family which may be, for example, dysprosium or gadolinium, and the chalcogen which may be sulfur, selenium or tellurium in stoichiometric proportions in a molar ratio of about 1:1:2. The resulting mixture of these three basic elements is then slowly fused under vacuum by sealing the mixture in quartz tubes, evacuating the same, and slowly heating the mixture over an extended time period at an elevated temperature, for example, of 1150° C. After the reaction to form the particular lanthanide chalcogenide is completed, the resulting product is cooled and may be analyzed during the cooling period by using X-ray powder diffraction to determine the crystal structure of the particular lanthanide chalcogenide compound. The pure crystallography phases of the lanthanide chalcogenide compounds can also be monitored by using x-ray crystallography.
Referring to FIGS. 1 through 4, the mixed metal chalcogenides of the invention have a crystal structure which is trigonal, tetragonal, orthorhombic or octahedral. FIG. 1 illustrates the crystal structure of the trigonal phase of the mixed metal chalcogenide AgErTe2, FIG. 2 illustrates the crystal structure of the tetragonal phase of the mixed metal chalcogenide AgDySe2, FIG. 3 illustrates the crystal structure of the orthorhombic phase of the mixed metal chalcogenide AgErSe2 and FIG. 4 illustrates the orthorhombic phase of the mixed metal chalcogenide CuDyS2.
Referring to FIGS. 5 and 6, the mixed metal chalcogenides of the invention can be produced as thin wafers, pellets or crystals that conduct electricity above a specific transition temperature Tc and are non-conductive below temperature Tc. Thus a current can be allowed to flow in an amplifier or signal generating circuit fabricated from the mixed metal chalcogenides of the invention when the material is warmed above Tc, but the current can be stopped as soon as the temperature drops below Tc. For example, FIG. 5 illustrates the conductivity of AgErSe2 as a function of temperature measured in degrees Kelvin, while FIG. 6 illustrates the conductivity of AgErTe2 as a function of temperature. As is best illustrated in FIG. 6, when the temperature of AgErTe2 is about 250° K., the material AgErTe2 transitions from a nonconductor (at temperatures below 250° K.) to a conductor (at temperatures above 250° K.). Thus, mixed metal chalcogenides of the invention can be used in electronic microcircuits as thermal "on-off" switches replacing conventional diode and transistor materials such as silicon and gallium arsenide.
It should also be noted that the mixed metal chalcogenide AgErTe2 has an electron conductive temperature dependency that parallels the low temperature superconductivity of yttrium barium copper oxide. This mixed metal chalcogenides is, in turn, superconductive at higher temperatures (about 250° K.) than the temperature at which yttrium barium copper oxide becomes superconductive.
The electrical components of the invention, in the general class of silver, copper or gold lanthanide chalcogenides, can be formed into electronic components or used in electronic "microchip" devices in conjunction with electrically conducting metals (such as copper, silver or gold) and non-conductors (such as silicon oxide or aluminum oxide insulators). The lanthanide chalcogenides hereof can be sputter-coated onto various substrates. The following are examples illustrating production of the mixed metal chalcogenides of the invention:
Silver Dysprosium Disulfide (AgDyS2).
A mixture was made of 108 grams of silver powder, 162.5 grams of dysprosium powder and 64 grams of powdered sulfur (1:1:2 molar ratio) under a nitrogen atmosphere in a glove box. About 3.0 grams of this mixture was placed in a 6 inch quartz tube which was evacuated and sealed under vacuum, using a high performance diffusion pump and a mercury manometer (vacuum was below 1 torr). The quartz tube was placed in a tubular furnace and was slowly heated to 1150° C. over a 5 day period. The mixture was held at 1150° C. for another 5 hours, then it was cooled to 700° C. over a week, and finally held at 650° to 700° C. for another 90 days. The quartz tube was then removed from the furnace and analyzed for purity using x-ray powder diffraction. The resultant material has a tetragonal form crystal structure.
Copper Gadolinium Disulfide (CuGdS2).
A mixture of 63.5 grams of copper powder, 157.25 grams of gadolinium powder and 64 grams of sulfur powder were mixed under nitrogen in a glove bag. About 3.5 grams of this mixture was placed in a 6 inch quartz tube, which was then evacuated and sealed under vacuum. The tube was slowly heated to 1150° C. for a period of 7 days, and then the tube was held at this temperature for another 8 hours. The tube was then cooled to 700° C. slowly, over a week, and was then held at 650° C. to 700° C. for 45 days. Finally, the tube was cooled to room temperature and the powder was removed. The powder was analyzed via x-ray diffraction (XRD) until the monoclinic phase was obtained.
Copper Erbium Disulfide (CuErS2).
Copper, erbium, and sulfur powders were mixed in 1:1:2 molar ratios under a nitrogen atmosphere. About 3.5 grams of this mixture was placed in a quartz tube which was evacuated and sealed under vacuum. The tube was slowly heated to 1150° C. over a 3 day period, held at 1150° C. for 3 hours, cooled to 700° C. over a week and held at 650° C. to 700° C. for 4 months. During this period the material was analyzed by x-ray powder diffraction until the orthorhombic phase was obtained.
Copper Dysprosium Disulfide (CuDyS2).
Copper, dysprosium, and sulfur powders were mixed in 1:1:2 molar ratios under a nitrogen atmosphere. About 3.5 grams of this mixture was placed in a quartz tube which was evacuated and sealed under vacuum. The tube was slowly heated to 1150° C. over a 3 day period, held at 1150"C. for 3 hours, cooled to 700° C. over a week and held at 650° C. to 700° C. for 3.5 months. During this period the material was analyzed by x-ray powder diffraction until the orthorhombic phase of FIG. 4 was obtained.
Silver Erbium Disulfide (AgErS2).
Silver, erbium, and sulfur powders were mixed in 1:1:2 molar ratios. About 3.0 grams of this mixture was placed in a quartz tube which, after evacuation, was sealed. The tube was slowly heated to 1150° C. over 10 days, held at 1150° C. for 6 hours, cooled to 700° C. over a week and held at 650° C. to 700° C. for 5 weeks. After this time the pure tetragonal phase was obtained, as indicated by x-ray powder diffraction.
Silver Gadolinium Disulfide (AgGdS2).
Silver, gadolinium, and sulfur powders were mixed in 1:1:2 molar ratios under a nitrogen atmosphere. About 3.0 grams of this mixture was placed in a quartz tube which was evacuated and sealed under vacuum. The tube was slowly heated to 1150° C. over a 7 day period, held at 1150° C. for 8 hours, cooled to 700° C. over a week and held at 650° C. to 700° C. for 1 month. During this period the material was analyzed by x-ray powder diffraction until the tetragonal phase was obtained. FIG. 8 illustrates the x-ray powder diffraction pattern for AgGdS2.
Silver Dysprosium Diselenide (AgDySe2).
Silver, Dysprosium and selenium powders were mixed in a 1:1:2 molar ratio. The mixture was placed in a quartz tube which was evacuated and sealed under vacuum. The mixture was slowly heated in the sealed quartz tube to 1150° C., followed by slow cooling to 550° C., at which temperature the samples were maintained for 3-4 months. During this period the material was periodically analyzed by x-ray powder diffraction until the single orthorhombic phase was obtained.
Silver Erbium Diselenide (AgErSe2).
Silver, erbium, and selenium powder were mixed in 1:1:2 molar ratio and placed in quartz tubes. The tubes were evacuated and sealed. The tubes were then heated over 3 days to 1150° C., held at this temperature for 2-3 hours and cooled over 2 days to 700° C., at which temperature the tubes were maintained for 3-4 months. During this period the material was periodically analyzed by x-ray powder diffraction until only the single tetragonal phase was obtained.
Silver Erbium Diselenide (AgErSe2).
Silver, erbium, and selenium powder were mixed in 1:1:2 molar ratio under a nitrogen atmosphere. About 3.5 grams of this mixture were placed in a quartz tube which was evacuated and sealed under vacuum. The tube was slowly heated to 1150° C. over a 3 day period, held at this temperature for 3 hours, cooled to 700° C. over a week and held at 650° C. to 700° C. for 4 months. During the 4 month period the material was analyzed until the single orthorhombic phase of FIG. 3 was obtained.
Silver Dysprosium Diselenide (AgDySe2).
Silver, Dysprosium and selenium powders were mixed in a 1:1:2 molar ratio, placed in quartz tubes, evacuated and sealed, heated over 3 days to 1150° C. and maintained at this temperature for 2-3 hours. The tubes were then cooled over 2 days to 700° C. and maintained at this temperature for 3-4 months. During this 3-4 month period the material was periodically analyzed by x-ray powder diffraction until only the single tetragonal phase of FIG. 2 was obtained.
Silver Erbium Ditelluride (AgErTe2).
Silver, erbium, tellurium powders were mixed in a 1:1:2 molar ratio, placed in quartz tubes, evacuated and sealed, heated over 3 days to 1150° C. and maintained at this temperature for 2-3 hours. The tubes were then slowly cooled to 600° C. and maintained at this temperature for a time period of 2-3 months. During this 2-3 month time period the material was periodically analyzed by x-ray powder diffraction until only a single trigonal phase, FIG. 1, was present.
Formation of Pellets.
A pellet was formed by uniaxial compression of 150 mg of silver lanthanum diselenide powder in a 0.125 inch diameter die at 3000 lbs. of force. Electrodes were applied as a gold powder on the front and back surfaces or the pellet, and the powder was pressed into a gold foil at 2000 lbs. The pellets were mounted in a spring loaded measurement cell and enclosed in a vessel of dry argon gas to keep out moisture. This entire apparatus, with the pellet specimens, was placed inside an environmental chamber where temperatures could be varied from -50° C. to +100° C.
Referring to FIGS. 1-4, Tables I, II, III and IV disclose the bond lengths and angles/atomic positions (X, Y, Z coordinates) for the single phase crystal structures respectively of FIGS. 1, 2, 3 and 4. It should be understood that any conventional and well known X-ray crystallography computer software program may be used to calculate the bond length and angles of the crystal structures illustrated in FIGS. 1, 2, 3 and 4. The pattern calculated for the trigonal space group P3m1, FIG. 1, is as follows:
TABLE I ______________________________________ X Y Z ______________________________________ Er 0.0 0.0 0.0Ag 1/3 2/3 0.413 Te (1) 1/3 2/3 0.776 Te (2) 1/3 2/3 0.254 ______________________________________ Bond Lengths: a = 4.30 Å- c = 7.00 Å-
The pattern calculated for the tetragonal space group I41 md, FIG. 2, is as follows:
TABLE II ______________________________________ X Y Z ______________________________________ Ag 0.0 0.0 0.54 Dy 0.0 0.0 0.00 Se (1) 0.0 0.0 0.23 Se (2) 0.0 0.0 0.77 ______________________________________ Bond Lengths: a = b = 5.53 Å- c = 11.803 Å-
The pattern calculated for the orthorhombic space group P2 1 21 21, is as follows:
TABLE III ______________________________________ X Y Z ______________________________________ Ag 0.296 0.379 0.002 Er 0.290 0.129 0.230 Se (1) 0.085 0.227 0.730 Se (2) 0.485 0.027 0.728 ______________________________________ Bond Lengths: a = 6.88 Å- b = 13.79 Å- c = 4.18 Å-
The pattern calculated for the orthorhombic space group P2 1 21 21, FIG. 4, is as follows:
TABLE IV ______________________________________ X Y Z ______________________________________ Ag 0.30 0.38 0.00 Dy 0.29 0.13 0.23 S (1) 0.08 0.23 0.73 S (2) 0.48 0.03 0.73 ______________________________________ Bond Lengths: a = 6.88 Å- b = 13.79 Å- c = 4.18 Å-
Electrical measurements were taken on pellets of the following mixed metal chalcogenides: ErCuS2 ; ErAgSe2 ; ErAgTe2 ; DyCuS2 and DyAgSe2. The pellets of these mixed metal chalcogenides were formed by uniaxially pressing approximately 150 mg of powder in a 0.125 diameter die at 3000 pounds of force. Electrodes were applied as Au powder and subsequently pressed at 2000 pounds force to form uniform thin foil contacts. The pellets were mounted in a spring loaded measurement cell and enclosed in a vessel containing a dry argon atmosphere. This spring loaded measurement cell was then placed inside an environmental chamber where temperatures were varied from -50° C. to +100° C. Pressed powder gold, that is a pressed sandwich of powdered gold, powdered ErAg2 Te2, for example, powdered gold, was found to provide excellent electrode contacts.
The conductivity of each sample of the above mixed metal chalcogenides was determined using a Solartron 1174 Frequency Response Analyzer over a wide frequency range (1-106 Hz). Complex impedance diagrams obtained in this fashion were interpreted using a laboratory computer program published as follows (M. Kleitz and J. H. Kennedy, "Fast Ion Transport in Solids", ed. P. Vashishta, J. N. Mundy and G. K. Shenoy, eds. p. 185, Elsevier/North Holland, Amsterdam, Netherlands (1979).
Referring to FIG. 9, with electrodes T1 and T2 the equivalent circuit 11 the mixed metal chalcogenide samples is illustrated in FIG. 9. The capacitor Cg is the geometric capacitance (˜10 pF), Cdl is the double layer capacitance (˜10 pF), Ri is the ionic transport resistance, and Re is the electronic transport resistance.
Small temperature intervals (4-5° C.) were employed to ascertain the existence and temperature for any phase transitions. Temperature of each sample was held constant with a Eurotherm controller for at least 10 minutes before impedance measurements were made to ensure thermal equilibrium.
Results for the electrical test for the mixed metal chalcogenides: CuErS2 ; AgErSe2 ; AgErTe2 ; CuDyS2 and AgDySe2 are summarized as follows:
Copper Erbium Disulfide (CuErS21).
This material was highly resistive. The DC resistivity tended to decrease with temperature. At low temperatures, the material was insulating. This was reflected in impedance spectra data for temperatures between -50° C. and +22° C., which depicted a virtually pure dielectric behavior of CuErS2 at these low temperatures. At a temperature of approximately 100° C., the DC conductivity was found to be 8×10-5 S/cm. Low frequency deviations became more severe at lower temperatures, as was found in data taken at 79° C. This scatter is coupled with the fact that the signal to noise ratio was low at the low frequency measurements.
Silver Erbium Diselenide (AgErSe2).
The impedance spectra was generally complex indicating a semiconductor Schottky contact was formed between the AgErSe2 pellet and the Au electrodes.
Silver Erbium Ditelluride (AgErTe2).
This material demonstrated very low resistance at all temperatures, with a resistivity less than 0.5 ohm-cm above 250° K. (see FIG. 6). The behavior of AgErTe2 was found to be metallic.
Copper Dysprosium Disulfide (CuDyS2).
Complex impedance measurements of this material were taken from 20° C. to 100° C. Due to high sample resistance, data below 100 Hz were obscured by noise. At room temperature (approximately 20° C.) conductivity values of 1.3×10-6 S/cm and capacitance values of 25 pF were obtained. The conductivity of the sample increased with temperature up to 62° C. and decreased with measurements taken at ≧74° C. After cooling the sample to room temperature, its conductivity returned to the initial value.
Silver Dysprosium Diselenide (AgDySe2), orthorombic phase.
Complex impedance measurements were taken from -50° C. to +100° C. At temperatures less that 0° C., data measurements taken at less than 103 Hz were obscured by noise. Conductivity was 1.0×10-6 S/cm at room temperature and capacitance was 275 pF. No reversal in conductivity increase with temperature was noted for DyAgSe2.
Referring to FIG. 7, there is shown a graph which illustrates the current flow in a nanoamps of a Silver Dysprosium Diselenide (AgDySe2) pellet as a function of the wavelength of incident light in nanometers. Thus, it can be seen that Silver Dysprosium Diselenide can be used in the fabrication of photo-electric devices such as optical couplers, optoisolators, light detectors and like optoelectronic devices.
It should also be noted that the mixed metal chalcogenides having the chemical formula AuDySe2 (Gold Dysprosium Diselenide) and the mixed metal chalcogenides having the chemical formula CuDySe2 (Copper Dysprosium Diselenide) exhibit similar electrical properties, that is each of these mixed metal chalcogenides generates a light induced photocurrent in response incident on the material.
From the foregoing, it may be seen that the invention provides a series of mixed metal chalcogenides in the form of a family of silver, copper and gold lanthanide chalcogenides having highly useful electrical characteristics over a wide range of temperatures. Obviously many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.
Claims (1)
1. A light sensitive material consisting of a mixed metal chalcogenides having the chemical formula AgDySe2 and having electrical properties, the electrical properties of said light sensitive material include generating a light induced direct current in response to light incident upon said light sensitive material in a range of about 400 nanometers to about 700 nanometers, said light induced direct current having a range of about 0.6 nanoamps to about 1.3 nanoamps.
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US08/283,478 USH1540H (en) | 1993-06-30 | 1994-07-29 | Electrical components formed of lanthanide chalcogenides and method of preparation |
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20050006653A1 (en) * | 2003-07-09 | 2005-01-13 | Samsung Electronics Co., Ltd. | Electrode layer, light generating device including the same and method of forming the same |
CN115894024A (en) * | 2022-09-27 | 2023-04-04 | 清华大学 | LaAgSeO thermoelectric material and preparation method and application thereof |
Citations (3)
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US2814004A (en) * | 1954-03-08 | 1957-11-19 | Gen Electric Co Ltd | Electrically semiconductive object and method of producing same |
US4061505A (en) * | 1971-10-08 | 1977-12-06 | Minnesota Mining And Manufacturing Company | Rare-earth-metal-based thermoelectric compositions |
JPS60191006A (en) * | 1984-03-12 | 1985-09-28 | Hitachi Ltd | Production of chalcogenide powder |
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1994
- 1994-07-29 US US08/283,478 patent/USH1540H/en not_active Abandoned
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
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US2814004A (en) * | 1954-03-08 | 1957-11-19 | Gen Electric Co Ltd | Electrically semiconductive object and method of producing same |
US4061505A (en) * | 1971-10-08 | 1977-12-06 | Minnesota Mining And Manufacturing Company | Rare-earth-metal-based thermoelectric compositions |
JPS60191006A (en) * | 1984-03-12 | 1985-09-28 | Hitachi Ltd | Production of chalcogenide powder |
Non-Patent Citations (6)
Title |
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"Rare Earth Copper Sulphides (LnCuS2)" by Murugesan et al.; Indian Journal of Chem. vol. 22A Jun. 1983 pp. 469-474. |
"Rare Earth Copper Sulphides, CulnS2 " by T. Murugesan et al. Proc. l. Phys. Solid State Phys. Symp. 25 (c) English pp. 123-124 (1982). |
Chemical Abstract No. 105:182, 672n by Agaev et al.; Chem. Abstracts vol. 105 No. 20 17 Nov. 1986 p. 697. * |
Chemical Principles by Marterton et al.; 4th ed. pub. by W. B. Saunders Co. 1977 p. 153. * |
Rare Earth Copper Sulphides (LnCuS 2 ) by Murugesan et al.; Indian Journal of Chem. vol. 22A Jun. 1983 pp. 469 474. * |
Rare Earth Copper Sulphides, CulnS 2 by T. Murugesan et al. Proc. Nucl. Phys. Solid State Phys. Symp. 25 (c) English pp. 123 124 (1982). * |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20050006653A1 (en) * | 2003-07-09 | 2005-01-13 | Samsung Electronics Co., Ltd. | Electrode layer, light generating device including the same and method of forming the same |
CN115894024A (en) * | 2022-09-27 | 2023-04-04 | 清华大学 | LaAgSeO thermoelectric material and preparation method and application thereof |
CN115894024B (en) * | 2022-09-27 | 2023-11-21 | 清华大学 | LaAgSeO thermoelectric material and preparation method and application thereof |
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