IE882450L - Doped BaTiO3 Based Compositions - Google Patents
Doped BaTiO3 Based CompositionsInfo
- Publication number
- IE882450L IE882450L IE882450A IE245088A IE882450L IE 882450 L IE882450 L IE 882450L IE 882450 A IE882450 A IE 882450A IE 245088 A IE245088 A IE 245088A IE 882450 L IE882450 L IE 882450L
- Authority
- IE
- Ireland
- Prior art keywords
- doped
- coform
- barium titanate
- less
- particle size
- Prior art date
Links
- 229910002113 barium titanate Inorganic materials 0.000 title claims abstract description 50
- 239000000203 mixture Substances 0.000 title claims description 32
- 239000002019 doping agent Substances 0.000 claims abstract description 53
- JRPBQTZRNDNNOP-UHFFFAOYSA-N barium titanate Chemical compound [Ba+2].[Ba+2].[O-][Ti]([O-])([O-])[O-] JRPBQTZRNDNNOP-UHFFFAOYSA-N 0.000 claims abstract description 49
- 239000002245 particle Substances 0.000 claims abstract description 49
- 238000009826 distribution Methods 0.000 claims abstract description 36
- 239000011164 primary particle Substances 0.000 claims abstract description 31
- 238000010191 image analysis Methods 0.000 claims description 14
- 238000004062 sedimentation Methods 0.000 claims description 13
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 5
- 239000010955 niobium Substances 0.000 claims description 5
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 4
- 229910052782 aluminium Inorganic materials 0.000 claims description 4
- 239000011651 chromium Substances 0.000 claims description 4
- 229910017052 cobalt Inorganic materials 0.000 claims description 4
- 239000010941 cobalt Substances 0.000 claims description 4
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 4
- 229910052758 niobium Inorganic materials 0.000 claims description 4
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 claims description 4
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims description 4
- 229910052721 tungsten Inorganic materials 0.000 claims description 4
- 229910052787 antimony Inorganic materials 0.000 claims description 3
- 229910052797 bismuth Inorganic materials 0.000 claims description 3
- 229910052742 iron Inorganic materials 0.000 claims description 3
- 229910052747 lanthanoid Inorganic materials 0.000 claims description 3
- 150000002602 lanthanoids Chemical class 0.000 claims description 3
- 229910052749 magnesium Inorganic materials 0.000 claims description 3
- 239000011777 magnesium Substances 0.000 claims description 3
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 claims description 3
- 229910052710 silicon Inorganic materials 0.000 claims description 3
- 239000010937 tungsten Substances 0.000 claims description 3
- 229910052727 yttrium Inorganic materials 0.000 claims description 3
- 229910052725 zinc Inorganic materials 0.000 claims description 3
- 239000011701 zinc Substances 0.000 claims description 3
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 2
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims description 2
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 claims description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 2
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 2
- WATWJIUSRGPENY-UHFFFAOYSA-N antimony atom Chemical compound [Sb] WATWJIUSRGPENY-UHFFFAOYSA-N 0.000 claims description 2
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 claims description 2
- 229910052796 boron Inorganic materials 0.000 claims description 2
- 229910052793 cadmium Inorganic materials 0.000 claims description 2
- BDOSMKKIYDKNTQ-UHFFFAOYSA-N cadmium atom Chemical compound [Cd] BDOSMKKIYDKNTQ-UHFFFAOYSA-N 0.000 claims description 2
- 229910052804 chromium Inorganic materials 0.000 claims description 2
- 239000010949 copper Substances 0.000 claims description 2
- 229910052802 copper Inorganic materials 0.000 claims description 2
- 229910052750 molybdenum Inorganic materials 0.000 claims description 2
- 239000011733 molybdenum Substances 0.000 claims description 2
- 229910052759 nickel Inorganic materials 0.000 claims description 2
- 239000010703 silicon Substances 0.000 claims description 2
- 229910052715 tantalum Inorganic materials 0.000 claims description 2
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 claims description 2
- 229910052720 vanadium Inorganic materials 0.000 claims description 2
- VWQVUPCCIRVNHF-UHFFFAOYSA-N yttrium atom Chemical compound [Y] VWQVUPCCIRVNHF-UHFFFAOYSA-N 0.000 claims description 2
- 239000012798 spherical particle Substances 0.000 claims 3
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims 1
- 229910052709 silver Inorganic materials 0.000 claims 1
- 239000004332 silver Substances 0.000 claims 1
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 claims 1
- 230000000877 morphologic effect Effects 0.000 abstract description 5
- 239000000047 product Substances 0.000 description 44
- 238000000034 method Methods 0.000 description 26
- 239000011133 lead Substances 0.000 description 15
- 229910052788 barium Inorganic materials 0.000 description 13
- 239000002002 slurry Substances 0.000 description 13
- 239000000243 solution Substances 0.000 description 13
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 12
- 230000015572 biosynthetic process Effects 0.000 description 12
- 239000011575 calcium Substances 0.000 description 12
- 239000010936 titanium Substances 0.000 description 12
- 150000001768 cations Chemical class 0.000 description 11
- 238000001354 calcination Methods 0.000 description 10
- 229910052791 calcium Inorganic materials 0.000 description 10
- 239000000843 powder Substances 0.000 description 10
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 9
- 150000003839 salts Chemical class 0.000 description 9
- 239000011135 tin Substances 0.000 description 9
- 229910052712 strontium Inorganic materials 0.000 description 8
- 238000003786 synthesis reaction Methods 0.000 description 8
- 229910052719 titanium Inorganic materials 0.000 description 8
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 6
- 239000000654 additive Substances 0.000 description 6
- 125000004429 atom Chemical group 0.000 description 6
- 239000000470 constituent Substances 0.000 description 6
- 238000003917 TEM image Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 238000003801 milling Methods 0.000 description 5
- 238000002360 preparation method Methods 0.000 description 5
- CIOAGBVUUVVLOB-UHFFFAOYSA-N strontium atom Chemical compound [Sr] CIOAGBVUUVVLOB-UHFFFAOYSA-N 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- 238000006467 substitution reaction Methods 0.000 description 5
- 229910052718 tin Inorganic materials 0.000 description 5
- 229910052726 zirconium Inorganic materials 0.000 description 5
- -1 alkali metal salts Chemical class 0.000 description 4
- 238000004458 analytical method Methods 0.000 description 4
- 238000005755 formation reaction Methods 0.000 description 4
- 150000004679 hydroxides Chemical class 0.000 description 4
- 238000000386 microscopy Methods 0.000 description 4
- 230000003472 neutralizing effect Effects 0.000 description 4
- 150000002823 nitrates Chemical class 0.000 description 4
- 238000003746 solid phase reaction Methods 0.000 description 4
- 125000005402 stannate group Chemical group 0.000 description 4
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 3
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 3
- 229910052783 alkali metal Inorganic materials 0.000 description 3
- 239000007864 aqueous solution Substances 0.000 description 3
- 239000000919 ceramic Substances 0.000 description 3
- 150000001805 chlorine compounds Chemical class 0.000 description 3
- 239000000706 filtrate Substances 0.000 description 3
- 239000012530 fluid Substances 0.000 description 3
- 238000009472 formulation Methods 0.000 description 3
- 238000001027 hydrothermal synthesis Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 239000002244 precipitate Substances 0.000 description 3
- 238000005245 sintering Methods 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- 230000000007 visual effect Effects 0.000 description 3
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 2
- 229910002651 NO3 Inorganic materials 0.000 description 2
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 2
- 150000001340 alkali metals Chemical class 0.000 description 2
- 235000011114 ammonium hydroxide Nutrition 0.000 description 2
- 238000013459 approach Methods 0.000 description 2
- RQPZNWPYLFFXCP-UHFFFAOYSA-L barium dihydroxide Chemical compound [OH-].[OH-].[Ba+2] RQPZNWPYLFFXCP-UHFFFAOYSA-L 0.000 description 2
- 229910001863 barium hydroxide Inorganic materials 0.000 description 2
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 150000001860 citric acid derivatives Chemical class 0.000 description 2
- 238000000975 co-precipitation Methods 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 239000000356 contaminant Substances 0.000 description 2
- 230000001186 cumulative effect Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000002939 deleterious effect Effects 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 150000004675 formic acid derivatives Chemical class 0.000 description 2
- 229910052735 hafnium Inorganic materials 0.000 description 2
- VBJZVLUMGGDVMO-UHFFFAOYSA-N hafnium atom Chemical compound [Hf] VBJZVLUMGGDVMO-UHFFFAOYSA-N 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000010335 hydrothermal treatment Methods 0.000 description 2
- 229910052748 manganese Inorganic materials 0.000 description 2
- 239000011572 manganese Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- QKKWJYSVXDGOOJ-UHFFFAOYSA-N oxalic acid;oxotitanium Chemical compound [Ti]=O.OC(=O)C(O)=O QKKWJYSVXDGOOJ-UHFFFAOYSA-N 0.000 description 2
- 239000002243 precursor Substances 0.000 description 2
- 238000004513 sizing Methods 0.000 description 2
- 239000007790 solid phase Substances 0.000 description 2
- 238000010671 solid-state reaction Methods 0.000 description 2
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonium chloride Substances [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- KRKNYBCHXYNGOX-UHFFFAOYSA-K Citrate Chemical compound [O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O KRKNYBCHXYNGOX-UHFFFAOYSA-K 0.000 description 1
- BDAGIHXWWSANSR-UHFFFAOYSA-M Formate Chemical compound [O-]C=O BDAGIHXWWSANSR-UHFFFAOYSA-M 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- 102100033979 Protein strawberry notch homolog 1 Human genes 0.000 description 1
- 235000001537 Ribes X gardonianum Nutrition 0.000 description 1
- 235000001535 Ribes X utile Nutrition 0.000 description 1
- 235000016919 Ribes petraeum Nutrition 0.000 description 1
- 244000281247 Ribes rubrum Species 0.000 description 1
- 235000002355 Ribes spicatum Nutrition 0.000 description 1
- 229910006724 SnOa Inorganic materials 0.000 description 1
- 239000004809 Teflon Substances 0.000 description 1
- 229920006362 Teflon® Polymers 0.000 description 1
- 229910010165 TiCu Inorganic materials 0.000 description 1
- LCKIEQZJEYYRIY-UHFFFAOYSA-N Titanium ion Chemical compound [Ti+4] LCKIEQZJEYYRIY-UHFFFAOYSA-N 0.000 description 1
- ZYCFPSLHSPMWDE-UHFFFAOYSA-N [Mn].[Nb].[Co] Chemical compound [Mn].[Nb].[Co] ZYCFPSLHSPMWDE-UHFFFAOYSA-N 0.000 description 1
- 150000001242 acetic acid derivatives Chemical class 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 101150029133 agmo gene Proteins 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-N ammonia Natural products N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 1
- 150000003863 ammonium salts Chemical class 0.000 description 1
- 229910001422 barium ion Inorganic materials 0.000 description 1
- DUPIXUINLCPYLU-UHFFFAOYSA-N barium lead Chemical compound [Ba].[Pb] DUPIXUINLCPYLU-UHFFFAOYSA-N 0.000 description 1
- 229910052454 barium strontium titanate Inorganic materials 0.000 description 1
- JXDXDSKXFRTAPA-UHFFFAOYSA-N calcium;barium(2+);oxygen(2-);titanium(4+) Chemical compound [O-2].[Ca+2].[Ti+4].[Ba+2] JXDXDSKXFRTAPA-UHFFFAOYSA-N 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- BFGKITSFLPAWGI-UHFFFAOYSA-N chromium(3+) Chemical compound [Cr+3] BFGKITSFLPAWGI-UHFFFAOYSA-N 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 239000002270 dispersing agent Substances 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000000921 elemental analysis Methods 0.000 description 1
- 238000002149 energy-dispersive X-ray emission spectroscopy Methods 0.000 description 1
- 238000005189 flocculation Methods 0.000 description 1
- 230000016615 flocculation Effects 0.000 description 1
- 239000012634 fragment Substances 0.000 description 1
- 239000000499 gel Substances 0.000 description 1
- 239000000017 hydrogel Substances 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 238000009616 inductively coupled plasma Methods 0.000 description 1
- 239000011872 intimate mixture Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000009533 lab test Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000001000 micrograph Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 150000003891 oxalate salts Chemical class 0.000 description 1
- 150000002978 peroxides Chemical class 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 230000010076 replication Effects 0.000 description 1
- 229910052706 scandium Inorganic materials 0.000 description 1
- SIXSYDAISGFNSX-UHFFFAOYSA-N scandium atom Chemical compound [Sc] SIXSYDAISGFNSX-UHFFFAOYSA-N 0.000 description 1
- 238000001350 scanning transmission electron microscopy Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 238000004611 spectroscopical analysis Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- UUCCCPNEFXQJEL-UHFFFAOYSA-L strontium dihydroxide Chemical compound [OH-].[OH-].[Sr+2] UUCCCPNEFXQJEL-UHFFFAOYSA-L 0.000 description 1
- 229910001866 strontium hydroxide Inorganic materials 0.000 description 1
- 230000003746 surface roughness Effects 0.000 description 1
- 150000003609 titanium compounds Chemical class 0.000 description 1
- CMPGARWFYBADJI-UHFFFAOYSA-L tungstic acid Chemical compound O[W](O)(=O)=O CMPGARWFYBADJI-UHFFFAOYSA-L 0.000 description 1
- GPPXJZIENCGNKB-UHFFFAOYSA-N vanadium Chemical compound [V]#[V] GPPXJZIENCGNKB-UHFFFAOYSA-N 0.000 description 1
- 238000004876 x-ray fluorescence Methods 0.000 description 1
Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G4/00—Fixed capacitors; Processes of their manufacture
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G27/00—Compounds of hafnium
- C01G27/006—Compounds containing, besides hafnium, two or more other elements, with the exception of oxygen or hydrogen
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G23/00—Compounds of titanium
- C01G23/003—Titanates
- C01G23/006—Alkaline earth titanates
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G25/00—Compounds of zirconium
- C01G25/006—Compounds containing, besides zirconium, two or more other elements, with the exception of oxygen or hydrogen
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/30—Three-dimensional structures
- C01P2002/34—Three-dimensional structures perovskite-type (ABO3)
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/01—Particle morphology depicted by an image
- C01P2004/04—Particle morphology depicted by an image obtained by TEM, STEM, STM or AFM
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/30—Particle morphology extending in three dimensions
- C01P2004/32—Spheres
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/51—Particles with a specific particle size distribution
- C01P2004/52—Particles with a specific particle size distribution highly monodisperse size distribution
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
- C01P2004/62—Submicrometer sized, i.e. from 0.1-1 micrometer
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
- C01P2004/64—Nanometer sized, i.e. from 1-100 nanometer
-
- 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
- C01P2006/12—Surface area
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Inorganic Chemistry (AREA)
- Power Engineering (AREA)
- Nanotechnology (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Crystallography & Structural Chemistry (AREA)
- Geology (AREA)
- Composite Materials (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Physics & Mathematics (AREA)
- Materials Engineering (AREA)
- Physics & Mathematics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Environmental & Geological Engineering (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Compositions Of Oxide Ceramics (AREA)
- Inorganic Insulating Materials (AREA)
Abstract
Dispersible, doped coforms of barium titanate are substantially spherical, intimately mixed on a particle size scale and submicron with narrow particle size distributions. The primary particle size of the doped coforms is in the range of 0.05 to 0.4 microns. The amount of dopant oxide or oxides contained in the coform ranges from greater than zero to 10 percent. Regardless of the dopant or dopants selected, all of the coforms are identified by the same, unique morphological characteristics.
[DE3826801A1]
Description
6 < ^67 DOPED BaTiOs BASED COMPOSITIONS The present invention relates to barium titanate based compositions and, more particularly, relates to dispersible, submicron, doped barium titanate coforns with narrow particle size distributions.
Barium titanate based compositions are extensively used in the electronics industry for the production of capacitors, condensers and PTCR (positive temperature coefficient of resistance) devices. Barium titanate is particularly useful and versatile in electronic applications since its electrical properties can be substantially modified by the incorporation of additives and/or dopants. The additives which are frequently employed are MAO® compounds, sshere M is a divalent cation and A is a tetravalent cation, having the BaTiO® perovskite structure. Typical additives include the titanates, zirconates and stannates of calcium, strontium, barium and lead. Since the additive or additives have the same crystal structure as BaTiOs, they readily form a solid solution during calcination or sintering. In general, additives represent more than 3 mole % of the BaTiOs, based formulation.
Dopants cover a aide range of metal oxides. These, in general, represent less than 5 mole % of the total BaTiOs. based formulation. The dopant or dopants employed may be completely or partially aiscible in the perovskite lattice or may be immiscible in the lattice. Examples of dopants employed include the oxides of La, the lanthanides, Y, Mb, Ta, Cu, Ho, W, Hn, Fe, Co, Mi, Zn, Al, Si, Sb and Bi. 1 ex In commercial practice, barium titanate based formulations are produced either by blending the required pure titanates, zirconates, stannates and dopants or by directly producing the desired powder by a high temperature solid state reaction of an intimate mixture of the appropriate stoichiometric amounts of the oxide or oxide precursors (e.g; carbonates, hydroxides or nitrates) of barium, calcium, titanium, etc. The pure titanates, zirconates, stannates, etc are also, typically, produced by a high temperature solid phase reaction process.
The prior art processes for producing barium titanate and barium titanate based compositions by solid phase reactions are relatively simple; nevertheless, they do suffer from several disadvantages. Firstly, the milling steps serve as a source of contaminants which can adversely affect electrical properties. Secondly, compositional iRhornogenieties, resul ting from incomplete mixing on a microscale, can lead to the formation of undesirable phases such as barium orthotitanate, Bas-TiCU, &?hich can give rise to moisture sensitive properties. Thirdly, during calcination, substantial particle growth and interpartic1e sintering occur. As a consequence, the milled products consist of irregularly shaped fractured aggregates sshich have a aide size distribution ranging from about 0.2 to about 10 microns. Moreover, it has been established that green bodies formed from such aggregated ponders with broad aggregate size distributions require elevated sintering temperatures and give sintered bodies aith broad grain size 2 d i str ibut ions.
Many approaches have been developed to try to overcome the limitations of the conventional solid state reaction processes. Precipitation of either doped barium titanyl oxalate or doped barium titanyl oxalate with partial substitution of strontium or lead for barium and zirconium for titanium is taught by Gallagher et al., "Preparation of Semiconducting Titanates by Chemical Methods", 46, J. Amer.Chem.Soc.. 359 (1963)5 Schrey, "Effect of pH on the Chemical Preparation of Barium-Strontium Titanate," 48, J. Amer.Cer.Soc. 401 (1965) and Vincenzini, "Chemical Preparation of Doped BaTiOs," Proceedings of the Twelfth Int. 1. Conf. Science of Ceramics, Vol. 12 p.151 (1983). The oxalates are decomposed at elevated temperature to form the doped barium titanate based compositions. US Patent number 3,637,531 teaches heating a single solution of dopant, titanium compound and alkaline earth salts to form a semisolid mass that is converted to the desired titanate based product by calcination. US Patent Mumber 4,537,865 discloses combining hydrous oxide precipitates of Ti, Zr,Sn, or Pb and hydrous oxides of the dopants with aqueous slurries of precipitated carbonates of Ba, Sr, Ca or Mg. The solids are calcined to give the required product. Kakega&a et al., "Synthesis of Mb-doped Barium Titanate Semiconductor by a yet-Dry Combination Technique" 4, J. Mat. Sci. Lets 1266 (1985) describe a similar synthesis procedure.
Mulder, "Preparation of BaTiOa and Other Ceramic Pouders by Coprecipitation of Citrates in an Alcohol", 49, Ceramic Bulletin 990-993 (1970) prepares doped BaTiO®, and BaTiOs based products by spraying an aqueous solution of citrates or formates of the constituents into an alcohol to effect dehydration and coprecipitation. The products obtained by calcination of the coprecipitated citrate or formate powders consist mostly of compact globules having sizes in the 3 to 10 micron range. US Patent No. 4,061,583 described doped BaTiOs based compositions prepared by addition of a solution of either the nitrates of chlorides of the required constituents to an aqueous alkaline solution containing hydrogen peroxide4. Decomposition oi the peroxide containing precipitate at about 100°C results in the formation of an amorphous BaTiO® based composition. Calcination of the amorphous product to about 600°C gives crystalline powders. Unfortunately, the primary particle sizes of the products are not characterised. Replication of some of the examples given in the patent indicated that the amorphous ponders had primary particle sizes Mhich Here substantially smaller than 0.05 microns.
Transmission electron micrographs of the products showed that the primary particles of the 600°C calcined products were aggregated.
In the above examples of typical prior art processes, calcination is employed xo complete the synethesis of the particles of the desired compositions. For reasons already noted, this elevated temperature operation is deleterious as it produces aggregated products which after comminution give smaller aggregate fragments uith Mide sise distributions. 4 US Patent numbers 4,233,282, 4,293,534 and 4,487,755 describe synthesising BaTiOs and BaTiO® based compositions through a molten salt reaction in which Ba is partially replaced by Sr and Ti is partially replaced by Zr. The products are characterised as being chemically homogeneous and consisting of relatively monodisperse submicron crystallites. Doped B&TiO® based products were not synthesised. Yoon et al., "Influence of the PTCR Effect in Semiconductive BaTiOs" 21 Mat. Bes. Bui 1429 (198S) teaches employing a molten salt process to synthesise products having the composition Bato .aoo—KiSf o.aoo Sb « TiOs where x has the values 0.001,0.002, 0.003 and 0.004. The bodies produced from the molten salt process exhibited greater effects on the PTCK in their resistivity-temperature characteristics and larger resistivities at room temperature and larger currant variations in current-time characteristics than the comparable specimens formed from powders produced by calcination of a mixture of the oxides and oxide precursors. The differences were attributed to the use of KC1 in the molten salt synthesis process and to the smaller size and size distribution of the grains in the samples derived. Although the molten salt based synthesis process can be used to give submicron doped products with narrow size distributions, the powders are inevitably contaminated with alkali metals,, since the molten salts consist of alkali metal salts. Of course, in most electronic applications alkali metals are deleterious contaminants.
Several aqueous based processes have been described for producing BaTiOs as well as BaTiO® based compositions where Ba is partially replaced by Sr and Ti is partially replaced by Sn or, possibly, by Zr. In the process taught in US Patent number 3*577,487 doped multicomponent alkaline earth and/or Pb (II) titanates, stannates, zirconates and/or hafnates are prepared. In these cases either the coprecipitated hydrogels are treated with alkaline earth hydroxides and subjected to the same treatment steps as those used for producing BaTiOs or the required gels and alkaline earth hydroxides are added to a preformed BaTiOs slurry which is then subjected to fluid energy milling and calcination. Unfortunately, the products prior to fluid energy milling, °*»ere not characterised. However, experience would indicate that the doped multicomponents products, prior to milling, should have specific surface areas in excess of 20 m3/g which indicates that the powder primary particle sizes are less than about 0.05 microns. Even after fluid energy milling at outlet temperatures in excess of 427°C, the multicomponent products cited in the examples had specific surface areas in excess of 18 ma/g. Calcination results in a further decrease in specific surface area.
This, for reasons already discussed, will lead to the format ion of aggregated products.
In our copending application, UK patent application number 8710244 (2190076A), multicomponent powders having the general formula Ba C 3. — sa — Si* — H fl * W'M" « 1 1 I S-y-y *-y" ) A y, A y°A y "Oas are disclosed where M equals Pb (II), M' equals Ca (11), M" 6 equals Sr (II), A equals Sn (IV), A* equals Zr (IV) and A" equals Hf (IV), x, x', x" and y, y' and y" represent the atom fractions of the divalent and tetravalent cations, respectively, each having independent values ranging from 0 to 0.3 so long as the sum of either (x-i-x'4-x") or (y+y'+y") does not exceed 0.4. The products having the abov.e nominal soichiometries were produced in a general hydrothermal process and were termed coforms. Each of the coforms was characterised as being stoichiometric, dispersible, submicron and having a narrow particle size distribution.
Doping of the barium titanate coforms was not investigated in the copending 8.710244. application. Hence, there is absent in the prior art any doped coforms of barium titanate which include calcium and/or lead or multiple divalent and tetravalent cation substitutions which are dispersible9 spherical and submicron with narrou particle size distributions.
Accordingly the present invention aims to provide a dispersible, submicron doped barium titanate coform with a narrou particle size distribution.
The present invention also aims to provide a wide variety of doped BaTiO®. based compositions of BaTiO® having primary particle sizes in the size range between 0.0b and 0.4 microns.
The doped barium titanate based composition will preferably have equiaxed primary particles, be substantially free of mill media and will further have all constituents intimately mixed on a particle size 7 scale.
Thus the present invention includes a Hide variety of dispersible, doped coforms of barium titanate which are substantially spherical, intimately mixed on a particle size scale and submicron with narrow particle size distributions. In one important embodiment of the present invention, the doped barium titanate based coform is represented by the general formula XBa t a—« ® jCat-t »0.YTi ? %—y—^ ® —y» >SnyZry y "O^b ZD^ therein X, Y and Z are coefficients with X and Y having a value betueen 0.9 and 1.1 and Z has a value greater than 2ero and less than 0.1, y8 y9 and y" have independent values ranging from zero to 0.3, the sum of y+y'+y" is less than 0.4, x? is greater than zero and less than 01.4 and D represents one or more dopant oxides.
In another important embodiment of the present invention, the doped barium titanate coform is represented by the general formula XBat i—s«> PbjatO. YTi c a—-y—y ~ ^ •• j SnyZry "Hi y Os. ZD wherein X, Y and Z are coefficients with X and Y having a value between 0.9 and 1.1 and Z has a value greater than zero and less than 0.1, y, y*, and y" have independent values ranging from zero to 0.3, the sum of y+y^+y" is less than 0.4, x is greater than zero and less than 0.4 and D represents one or more dopant oxides.
In a further important embodiment of the present invention, the barium titanate coform is represented by the general formula 8 Xj^&c %—K—k ° - h " > FbxCa« ®SrK "Of YTi c i-y"ye*-y")SnyZryuH!3r"03. ZD wherein X, Y and Z are coefficients &Jith X and Y having a value between 0.9 and i.l and Z has a value greater than sero and less than 0.1, x» x', x", y, y1 and y" each have independent values greater than zero and less than 0.3, the sum of x+x'-s-x" is less than 0.4, the sum of y+y'+y" is less than 0.4 and D represents one or more dopant oxides.
Each of the doped barium titanate based coforms of the present invention possess the same unique physical properties. The mean primary particle size of the doped barium titanate based coforms is in the range of 0.05 to 0.4 microns. Koreover9 the mean particle size as determined by image analysis is comparable to the mean particle size determined by sedimentation demonstrating that the coforms are dispersible. The size distribution curve of the doped coform particles has a quartile ratio less than or equal to 2.0 which establishes that the doped barium titanate based coforms have a fairly narrou particle size distribution. Additionally, significant is the fact that any of the dispersible., submicron doped barium titanate dielectric compositions of the present invention can be produced by a single, general hydrothermal process.
These and other details and advantages of the invention Rill be described in connection Hith the accompanying drawings in which; Fig 1 is a transmission electron micrograph at 50,000x magnification of a dispersible, submicron multiple dopant complex coform according to the present invention having the general formula 9 1. 02B&O . ® 5. a. Pbo . looCfto. os iSro. oosO. T i o. easSllo. ©-p«ftZr o. oss0a 0.012CoO. 0.009Mn0 . 0.005Mb30= and Fig 2 is a transmission electron micrograph at 50,000x magnification of a single dopant complex barium titanate coform, having the general formula 0.998B&o. TsaPbo. lo-'iCao. ossSro. oo®0. Tio. ssiSno. ovoZro. ossOa. 0. 03CoO ahich exhibits a morphology substantially similar to the morphology of the complex doped coform of Fig 1.
The preferred embodiment of the present invention is a doped coform of the general type > PbjtCa** «SrM»0. YTi < %—y—y * — y •• >Sn yZr y» H t y •• Ose .ZD therein K,Y and Z are coefficients for the divalent, tetravalent and dopant cations nith X and Y having a value Within the range 0.9 to 1.1 and more preferably within the range 0.95 to 1.05 and Z has a value from greater than 0 to 0.1 and more preferably from greater than 0. to 0.05, x9 x'3 x" represent the atom fractions of the divalent cations and have independent values ranging from greater than zero to 0.3 and, more preferably, from greater than zero to 0.2 and the sum xh-x9+x" has a value ranging from greater than zero to 0.4 and more preferably from zero to 0.3, y, y? and y" represent the atom fractions of the tetravalent cations and have independent values ranging from greater than zero to 0.3, and more preferably, from greater than zero to 0.25 and the sum of y+y*+y" has a value ranging from greater than zero to 0.4 and, more preferably, from greater than zero to 0.3. D represents the di fferent dopant oxides of the bar ium t itanate coform.
Preferably, the fine, dispersible submicron ponder of the present invention consists of a doped barium titanate coform having both a tetravalent and a divalent metal ion substitution of between greater than sero and 30 mole percent. The divalent barium ion can be partially replaced by either lead, calcium, strontium, or mixtures thereof. Additionally, the tetravalent titanium ion can be partially replaced by tin, sirconium, hafnium or mixtures thereof.
The barium titanate based compositions are doped with small amounts of one or more of a variety of dopants including the oxides of the lanthanides, cobalt, manganese, magnesium,, scandium, yttrium, antimony, bismuth, zinc, cadmium, aluminum, boron,tungsten, chromium, nickel, molybdenum, iron, niobium, vanadium, tantalum, copper, silicon and mixtures thereof. The amount of dopant oxide or oxides contained in the coform ranges from between greater than zero to 10 mole percent and preferably from greater than 2ero to 5 mole percent. Notuithstanding with dopant or combination of dopants is employed in the barium titanate coform, the barium titanate based compositions are uniquely identified by the aforementioned morphological characteristics. Hence, both the single dopant as well as multiple dopant complex coforms of barium titanate consist of substantially spherical, dispersible particles having a primary particle size in the range of 0.05 and 0.4 microns with narrow size distribution.
The preferred approach for producing the doped barium 11 ? titanate based coforms is to intimately mix the dopant or dopants with the tetravalent hydrous oxide or oxides. Intimate mixing can be accomplished by one of a variety of methods. Dopants may be coprecipitated with the tetravalent hydrous oxides. Alternatively, the dopants can be precipitated as high surface area hydrous oxides, cashed and then combined uith the tetravalent hydrous oxides. Finally, since the dopants can be precipitated in an alkaline media containing Ba(II), their solutions, preferably either as salts of acetates, formates or nitrates or as ammonium salts can be added to the tetravalent hydrous oxides. The slurry of hydrous oxides and dopants is hydrothermally treated with the oxides or hydroxides of lead and/or calcium at temperatures up to 200°C. Thereafter, the slurry is cooled to a temperature between 60 and 150°C. A solution of barium hydroxide4 or barium hydroxide partially replaced by strontium hydroxide, heated to a temperature between 70°C and 100°C is added at a constant rate mithin a time period of 0.1 to 12 minutes to the insoluble divalent cation, tetravalent hydrous oxide and dopant slurry. The slurry is held at the addition temperature for 10 to 30 minutes and then heated to a temperature between 120°C to 22b°C to ensure that the required degree of reaction of the hydrous oxide with the soluble divalent cation hydroxide occurs.
The primary particle size and size distribution of the coforms produced by the hydrothermal process are the same 12 whether the doped barium titanate coforms contain simply a single dopant or instead contain several dopants. This becomes readily apparent from the transmission electron micrograph of the multiple dopant complex coform, 1 • 02B&O . & i i F bo. loeaCa©. oeiSro. oo® 0. T io. essSllo. of^Zro. . 0. 012CoO. 0. 009"firk 0. 0. 005Mba0os in Fig 1 which shows the presence of predominantly single, substantially spherical primary particles, having a primary particle size of 0.20 microns with a quartile ratio of 1.29 uhich indicates that the product has a narroa primary particle size distribution. A comparison of the multicomponent doped complex barium titanate based coform of Fig 1 aith a transmission electron micrograph of a single dopant barium titanate coform, 0.998Ba0.TszPbo.to«CSo.oea Sr0 . ooaO. T i o. ess i Sn0 „ OTO Zro.oesOa •0.03Co0, in Fig 2 indicates that the morphologies of each of the barium titanate based compositions are very similar. This is further substantiated by the image analyses results which show that the product of Fig 2 has a primary particle size of 0.18 microns and a quartile ratio of 1.26.
In order to evaluate the physical and chemical properties of the doped barium titanate based coforms for the present invention, a variety of laboratory tests uere performed. Reagent grade chemicals or their equivalents were used throughout. The Ba(0H)s 8HS0 products employed contained either about 1.0 mole or 0.3 mole percent Sr uhich tends to concentrate in the product. All solutions of Ba(0H)a5 maintained at 70 to 90°C9 Mere filtered prior to use to remove any carbonate present. CaCOs was calcined at 800°C to give CaO. The latter compound uhen contacted &ith 13 aater gives Ca(OH)a. Tungsten Has introduced as an ammonium tungstate solution. This uas prepared by dissolving tungstic acid, WO® H20, in heated 2H ammonia solution with stirring; the solution formed °*sas metastable and was used shortly after its preparation.
Hydrous oxides of TiOa, SnOs and ZrOs were prepared by neutralising aqueous solutions of their respective chlorides Hith aqueous ammonia at ambient temperatures. The products Mere filtered off and Hashed until chloride-free filtrates, as determined by AgMO®, sere obtained. A hydrous Nb(V) oxide uas similarly prepared by neutralising a solution of the flouride of Mb (V). Mixed hydrous oxides of Ti03 and SnOa, and TiOa and Sb3Os Here similarly prepared by neutralising solutions containing the chlorides of Ti(IV) and Sn(IV) and Ti(IV and Sb(III), respectively. A coprecipitate of hydrous TiOse and BiaOs was prepared by neutralising an aqueous solution containing Ti(IV) chloride and Bi (III) nitrate. The percent solids present in the cashed wet cakes Has determined after calcination for one hour at 900oC. Several net cakes of each product were used during the course of the nork. h11 synthesis experiments Here performed in a 21itre autoclave. To prevent contamination all wetted parts of the autoclave Here either wade of titanium metal or Here coated uith Teflon a. All synthesis experiments Mere performed in the absence of Cos. Filtered solutions of Ba(OH)se, maintained at a temperature of about 80°C, Here introduced into the autoclave either by means of a high pressure pump 14 or, for rapid addition, by discharging a solution of the Ba(OH);s, contained in a heated bomb, within 10 seconds into the autoclave by means of high pressure Nss. The contents of the autoclave were stirred by means of a one inch diameter turbine type stirrer, operated at 1000 to 1500KPM during the synthesis process. After synthesis, the resulting slurries were transferred to a pressure filter without exposure to the atmosphere (to prevent formation of insoluble BaCOs), filtered and dried in vacuum at 100°C.
Image analysis was used to determine product primary particle size and primary size distribution. These were determined by sizing 500 and 1000 particles in a plurality of TEH fields so as to obtain the equivalent spherical diameters of the primary particles. Two or more touching particles were visually disaggregated and the sizes of the individual primary particles were measured. The equivalent spherical diameters were used to compute the cumulative mass percent distribution as a function of primary particle size. The median particle size, by weight, was taken to be the primary particle size of the sample. The quartile ratio, QS defined as the upper quartile diameter (by weight) divided by the lower quartile diameter, was taken as a measure of the width of the distribution. Monodisperse products have a QK value of 1.0. Products with QB values in the range of 1.0 to 1.5 were classified as having narrow size distributions; those with Q1 values ranging from 1.5 to about 2.0 were classified as having Moderately narrow size distributions while those with QK values greater than about 2.0 were classified as having broad size distributions.
Experience indicated that the doped coforms could be classified as having narrow, moderately narrow and broad size distributions by a visual examination of the TEM's. Based on this experience, visual examination was used to classify particle size distribution of the products of this work. Since the vast majority of the doped coforms produced had narrow size distributions, in this work, average primary particle size was reliably determined by sizing 20 to 30 particles in the micrographs. Both the quantitive and serai-quantitive size measurement procedures indicated that the doped barium titanate based coforms have primary particle sizes in the range between 0.05 and 0.4 microns.
Particle size was also calculated from surface areas determined by nitrogen adsorption. In these calculations the densities of the products were calculated from the composition of the powders and the literature densities of the pure component perovskites. Since the amounts of dopants m the samples are small, and since the dopants, typically, have densities which are not very different from those of the perovsk1tes of interest, the effect of dopant on product density Mas intentionally ignored. The error introduced by this approximation is small.
It should be mentioned that an exact correspondence between particle size determined by microscopy and by surface area can only be expected for monodisperse spherical powders. hs the distribution broadens, the degree of sphericity decreases and particle surface roughness increases, the difference between particle sizes determined 16 by the two techniques increases. Thus, in real systems particle size determined by microscopy is9 typicallys larger than the size calculated from surface area. In this work, agreement with a factor of ti^o between the tao size measurements was taken as evidence that the amounts of fine sized precipitates associated uith the particles was small.
Produce dispersibi1ity was assessed by comparing the primary particle size and size distributions determined by image analyses with the comparable values determined by sedimentation procedures. The sedimentation process gives the particle Stokes diameter ^hich, roughly, corresponds to the equivalent spherical diameter determined by image analysis. In this work, a Hicromeritics Serigraph (Morcross, Georgia) »as employed to determine cumulative »ass percent distributions in terms of Stokes diameters from uhich the median Stokes diameters and the QK values were calculated.
Prior to sedimentation, the ponders were dispersed by a 15 to 30 minute sonification in isopropanol containing 0.12 weight percent Emphos PS-21A (Hitco Organics Division, 520 Madison Ave., Neu York) as a dispersant.
Particle sizes determined by sedimentation and by image analysis depend on different principles. For this reason an exact correspondence in size by these two methods is not always obtained. Further, as already noted, in image analysis touching particles, some of uhich may be bonded together, are visually disaggregated. In the sedimentation process both touching and bound particles act as single 17 entities. These entities occur both because of the existence of bonding (e.g; necking) between some of the primary particles forming cemented aggregates which cannot be readily broken down during the sonification process and because of less than optimum dispersion stability which leads to some flocculation. In this uork, agreement Within a factor of two between the median weight sizes, determined by image analysis and by sedimentation„ was taken as one indication that the products were dispersible. Also,. QR values determined by sedimentation are expected (and found) to be larger than those found by image analysis. It is reasonable to assume that under optimum dispersion conditions the QR value Hill lie between the values determined by image analysis and by sedimentation. In this work, the additional criterion used to determine dispersibi1ity Mas that the QR values of the powders obtained by sedimentation uas.smaller than 2.0.
A qualitive procedure was also used to assess dispersibi1ity. Experience in this work showed that products could be classified as being dispersible if the bulk of the primary particles in the TEMss were present as single particles. This qualitative assessment of dispersibi1ity Hill satisfy the quantitative criteria described above for characterising dispersibi1ity.
Sample uniformity taas determined by scanning transmission electron microscopy having an energy dispersive X-ray analysis capability. The composition of several primary particles were determined. The product was judged to be uniform, on a particle size scale, if at least 80% of the particles contained all the ponder constituents. In practice, where TEH analysis was performed, this criterion was always met. Moreover, the amounts of the various constituents, although not quantified, appeared from peak intensities to be reasonably comparable (within 80%) on a particle to particle basis.
Product composition was determined by elemental analysis, using inductively coupled plasma spectroscopy, IPC, after sample dissolution. The precision of the analyses for the major constituents was about + 2%. The precision of the results for the minor elements Mas less than this figure. The Ba(11)/Ti(IV) atom ratios of samples which consisted predominantly of BaTiO® were also determined by X-ray fluorescence. These ratios are somewhat more precise than those determined by solution analysis and have been employed where applicable.
The doped barium titanate coforms according to the present invention include coforms having a partial substitution of divalent lead or calcium for the divalent barium. The doped coforms also include coforms in which the divalent barium is partially replaced by mixtures of lead and calcium or mixtures of lead, calcium and strontium. Partial replacement of the tetravalent titanium cation by tin, zirconium and hafnium is also within the scope of the invention. As shown in our copending application regardless of the particular divalent 19 or tetravalent cation substitution, the morphological characteristics of the barium titanate coforras are the same. Consequently, the following non-limiting examples include only the more complex coforms of barium titanate but are intended to provide equally representative teachings of the morphological characteristics of doped coforms of barium lead titanate and barium calcium titanate and tetravalent cation modifications thereof.
EXAMPLE 1 k series of coforms containing a single dopant were prepared by heating, from room temperature to 200°C in about 70 minutes, 0.64 L of a vigorously stirred slurry containing, in moles. 0.167 TiOst 0.066 Sn, 0.02 Zr03a 0.022 PbO, 0.022 CaO and 0.006 dopant salt added as a nitrate. The slurry Mas cooled to 120°C and 0.46 L of Ba(0H)ai solution heated to between 70 and 90°C, containing about 0.21 moles Ba(0H)x fc°as added to the slurry in 3.0 + 0.2 minutes. The resulting slurry temperature u&s held at 120°C for approximately 30 minutes and then heated to 200°C in about 30 minutes. The slurry samples were filtered and dried and then surface area, chemistry and morphological characteristics aers determined. * t Atom Ratio In Solids Dopant Ba Pb Ca Sr Ti Sn Zr Dopant Co( II) 0. 790 0. 104 0. 098 0. 006 0. 831 0.070 0.099 0. 030 Hn(11) 0.819 0. 107 0. 105 0.006 0. 828 0.072 0.100 0. 030 Lad II) 0. 802 0. 100 0. 085 0. 006 0. 841 0.080 0.087 0. 027 Cr( III) 0.792 0. 102 0. 098 0.006 0. 830 0.072 0.098 0. 032 Dopant X/Y Rat io Area (m 2/g) Partic Area ■ 1 e i Si: I ze Size TEH Distribut ion Co( 11) 0.998 Hn(11 ) 1.037 La(111) 0.993 Cr(III) 0.998 .8 0.09 12.4 0.08 .9 0.09 10.9 0.09 0. 18 Narrou 0.15 Narrow 0. 19 Narrou 0.19 Narrow The concentrations of the dopants and the tetravalent hydrous oxides in the filtrates were all belo&i the detection limits of the equipment (less than 1 x 10~* aoles/L). It therefore can be assumed that these Metals Mere almost quantitatively incorporated in the solid phase. The TEW3s showed that the product particles are substantially spherical and submicron. The particle size determined from the surface area agreed uithin a factor of two ?4ith the particle s ize determined by microscopy, indicating that little £ine-sized material Mas associated faith the particles, All the doped coforms are classified as being dispersible. Visual examination of the TEM's of the cobalt doped product indicated a quartile ratio of 1.26. The TEM's of the other products mere visually assessed and 21 found to have similar size distributions. A quantitative assessment of dispersibi1ity, using the sedimentation procedure, was obtained for the manganese doped product.
This procedure shows that the product has a particle size of 0.21 microns, a value which agrees well with the particle size obtained from TEM's, and a quartile ratio of 1.69. These quantitive data confirm that the product is dispersible.
EXAMPLE 2 Complex coforms containing three dopants were prepared by hydrothermal treatment using comparable amounts and sources of the tetravalent hydrous oxides and the alkaline earth and Pb(II) cations employed in Example 1. 0.002 moles of each dopant as nitrate salts or, in the case of niobium, as a Mb (OH)® aet cake, were added to the tetravalent hydrous oxide slurry prior to the barium hydroxide addition. After the hydrothermal treatment process it was found that the solid phase tetravalent and divalent atom ratios uere comparable to those in Example 1 and are not reported here.
Dopant Hole Ratio X/Y Area Particle Size Dopant Oxides Ratio (m2/g) (microns) To Perovskite Area TEM Cot II) Mb (V) 0.031 1.035 10.0 0.10 0.20 Hn ( U ) 22 Cr(111) Co( 11 ) 0.024 1.034 12.6 0.08 0.15 Al ( I I I) About 50 to 60% of the A1(111) reported to the filtrate and, accordingly, the mole ratio of these dopant oxides to the perovskite, that is,, the value of the coefficient Z9 for the chromium-cobait-aluminum doped coform yas smaller than that for the cobalt-niobium-manganese doped coform. All the products appeared to be substantially spherical, dispersible and had narrou size distributions. Image analysis demonstrated that the cobalt-niobium-snanganese doped coform had a primary particle size of 0.20 microns and a quartile ratio of 1.29. Sedimentation studies showed that the product has a particle size of 0.25 microns and a quartile ratio of 1.67. These quantitive measurements confirm the qualitative assessments that the products are dispersible and have narrow size distributions. Further indicative of dispersibi1ity is the agreement within a factor of two between the particle size determined by microscopy and from surface area calculations. The cobalt-niobiurn-manganese doped complex barium titanate coform was subjected to a TEM analysis. 23 to It was found that the particles all contained barium,, lead, calcium, strontium,, titanium, zirconium, tin, manganese, cobalt and niobium in roughly comparable amounts. The TEH results demonstrate that the multi-doped complex coforms of barium titanate are homogeneous on a particle size scale. 24 Fv
Claims (10)
1. A doped barium titanate based coform comprising substantially spherical particles having the formula XBa t i—x-i •• > Ca« » 0. YTi i a—y—y»— y- >SnyZry"Hfy"03e.ZD wherein X and Y have values between 0.9 and 1.1, Z has a value greater than zero and less than 0.1, y, ys and y" have independent values ranging from zero to 0.3, the sum of y + y' + y" is less than 0.4, x* is greater than zero and less than 0.4 and D is at least one dopant oxide therein the mean primary particle size of the doped coform is in the range of 0.05 and 0.4 microns.
2. A doped barium titanate based coform comprising substantially spherical particles having the formula XBa c i—si > PbjtO. YTi c s. —y—y • — y > Sn yZr y • H f y ■■ O3 .ZD wherein X and Y have values between 0.9 and 1.1, Z has a value greater than zero and less than 0.1, y, y' and y" have independent values ranging from zero to 0.3, the sum of y t y' + y" is less than 0.4, x is greater than zero and less than 0.4 and D is at least one dopant oxide, wherein the mean primary particle size of the doped coform is in the range of 0.05 and 0.04 microns.
3. The doped coform of barium titanate of claim 1 or 2 wherein the doped coform has a narrow particle size distribution as determined by image analysis and the prissary P&rticle size distribution curve of the doped coform has a quartile ratio less than or equal to 2.0.
4. A doped barium titanate based coform comprising substantially spherical particles having the formula 25 XBa CI — K — x 1 — K " ) PbsfCSLK * Sr s*"0»Yli t 1 — y —y * — y " ) SltyZr y ^ H* y " * ZD wherein X and Y have values between 0.9 and 1.1, Z has a value greater than zero and less than 0.1, x, x5 and x", y, y- and y" each have independent values greater than zero and less than 0.3, the sum of x + x9 + x" is less than 0.4, the sum of y + y' + y" is less than 0.4, and D is at least one dopant oxide, therein the wean primary particle size of the doped coform is in the range of 0.05 and 0.4 microns.
5. The doped coform of barium titanate of any one of claims 1-4 wherein at least one dopant oxide D is selected from the group consisting of oxides of lanthanides, cobalt, manganese, magnesium, yttrium, bismuth, aluminum, boron, tungsten, niobium, chromium, nickel, molybdenum, iron, antimony, vanadium, tantalum, copper, silver, zinc, cadmium, silicon and mixtures thereof.
6. The doped coform of barium titanate of any one of claims 1-5 therein the primary particle sizes determined by image analysis and by sedimentation agree within a factor of two.
7. The doped coform of barium titanate of any one of claims 4-6 wherein the doped coform has a narrow particle size distribution as determined by image analysis and the primary particle size distribution curve for the doped coform has a quartile ratio less than or equal to 1.5.
8. The doped coform of barium titanate of any one of claims 1-7 wherein the ratio X/Y is 1.000 4- 0.015. 26
9. The doped coform of barium titanate of any one of claims 1-wherein the ratio X/Y is within the range between 0.95 and 1.1.
10. A doped barium titanate as claimed in claim 1 substantially hereinbefore described by way of Example. TONKINS & CO.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US8504387A | 1987-08-12 | 1987-08-12 |
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| IE882450L true IE882450L (en) | 1989-02-12 |
| IE61487B1 IE61487B1 (en) | 1994-11-02 |
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| IE245088A IE61487B1 (en) | 1987-08-12 | 1988-08-11 | Doped BaTi03 Based Compositions |
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| JP (1) | JP2532599B2 (en) |
| KR (1) | KR970004271B1 (en) |
| CN (1) | CN1016962B (en) |
| DE (1) | DE3826801C2 (en) |
| ES (1) | ES2006956A6 (en) |
| FR (1) | FR2619370B1 (en) |
| GB (1) | GB2208644B (en) |
| HK (1) | HK994A (en) |
| IE (1) | IE61487B1 (en) |
| IT (1) | IT1226738B (en) |
| MX (1) | MX169172B (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| DE19635406B4 (en) * | 1996-08-31 | 2005-09-01 | Philips Intellectual Property & Standards Gmbh | Capacitor and multilayer capacitor with a tungsten-containing BCZT ceramic dielectric |
| DE19744857A1 (en) * | 1997-10-10 | 1999-05-06 | Fraunhofer Ges Forschung | Nanocrystalline sensor and manufacturing process |
| CN1054166C (en) * | 1997-11-14 | 2000-07-05 | 中国科学院固体物理研究所 | Preparing method for inlaid dimension controllable nanometre grade silver particle on barium titanate film |
| CN1126717C (en) * | 1998-07-01 | 2003-11-05 | 卡伯特公司 | Hydrothermal process for making barium titanate powders |
| JP4446324B2 (en) | 2001-09-27 | 2010-04-07 | 株式会社村田製作所 | Dielectric porcelain composition and capacitor using the same |
| JP4201242B2 (en) * | 2002-03-26 | 2008-12-24 | Ｔｄｋ株式会社 | High dielectric constant dielectric ceramic composition |
| US6960546B2 (en) * | 2002-09-27 | 2005-11-01 | Paratek Microwave, Inc. | Dielectric composite materials including an electronically tunable dielectric phase and a calcium and oxygen-containing compound phase |
| EP2328193B1 (en) * | 2009-11-30 | 2015-03-11 | Canon Kabushiki Kaisha | Piezoelectric ceramic, method for making the same, piezoelectric element, liquid discharge head, and ultrasonic motor |
| CN113603498B (en) * | 2020-12-30 | 2022-09-30 | 苏州金宏气体股份有限公司 | Cobalt-doped BaTiO 3 Piezoelectric ceramic, preparation method thereof and high-purity hydrogen production |
| CN112759385B (en) * | 2021-01-06 | 2021-12-14 | 中国科学院福建物质结构研究所 | Perovskite ceramic material and preparation method and application thereof |
| CN115872735B (en) * | 2022-11-18 | 2024-01-16 | 广东工业大学 | Zirconium tin hafnium lanthanum lead acid ceramic, preparation method and energy storage application thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3637531A (en) * | 1970-05-01 | 1972-01-25 | Texas Instruments Inc | Method for making ceramic titanate elements and materials therefor |
| US4061583A (en) * | 1974-03-13 | 1977-12-06 | Murata Manufacturing Co., Ltd. | Preparation of titanates |
| JPS5552211A (en) * | 1978-10-13 | 1980-04-16 | Suwa Seikosha Kk | Temperature compensating capacitor and method of manufacturing same |
| DE2941304A1 (en) * | 1978-10-13 | 1980-04-30 | Suwa Seikosha Kk | DIELECTRICAL, METHOD FOR THE PRODUCTION THEREOF, AND THEIR USE IN CAPACITORS FOR TEMPERATURE COMPENSATION PURPOSES |
| US4233282A (en) * | 1979-10-18 | 1980-11-11 | General Electric Company | Molten salt synthesis of barium and/or strontium titanate powder |
| EP0043157B1 (en) * | 1980-06-30 | 1984-08-08 | Centralab Inc. | Ceramic dielectric for base metal electrode capacitors and method of manufacture |
| US4293534A (en) * | 1980-08-22 | 1981-10-06 | General Electric Company | Molten salt synthesis of alkaline earth titanates, zirconates and their solid solutions |
| DE3106136A1 (en) * | 1981-02-19 | 1982-08-19 | Draloric Electronic GmbH, 8672 Selb | Process for producing polycrystalline ceramic PTC thermistor bodies |
| US4487755A (en) * | 1982-07-01 | 1984-12-11 | General Electric Company | Preparation of large crystal sized barium and/or strontium titanate powder |
| US4537865A (en) * | 1984-07-11 | 1985-08-27 | Murata Manufacturing Co., Ltd. | Process for preparing a particulate ceramic material |
| JPS6131345A (en) * | 1984-07-25 | 1986-02-13 | 堺化学工業株式会社 | Manufacture of composition |
| JPS61111957A (en) * | 1984-11-02 | 1986-05-30 | 堺化学工業株式会社 | Composition for ceramic dielectric |
| MX172902B (en) * | 1986-05-05 | 1994-01-20 | Cabot Corp | BARIO TITANATE COFORMS |
| DE3723082C2 (en) * | 1986-07-14 | 2003-09-25 | Cabot Corp | Process for the production of submicron perovskites |
| GB2193713B (en) * | 1986-07-14 | 1990-12-05 | Cabot Corp | Method of producing perovskite-type compounds. |
-
1988
- 1988-05-24 ES ES8801633A patent/ES2006956A6/en not_active Expired
- 1988-08-06 DE DE3826801A patent/DE3826801C2/en not_active Expired - Fee Related
- 1988-08-10 MX MX012622A patent/MX169172B/en unknown
- 1988-08-10 GB GB8818969A patent/GB2208644B/en not_active Expired - Fee Related
- 1988-08-11 IE IE245088A patent/IE61487B1/en not_active IP Right Cessation
- 1988-08-11 FR FR8810833A patent/FR2619370B1/en not_active Expired - Fee Related
- 1988-08-12 IT IT8821706A patent/IT1226738B/en active
- 1988-08-12 CN CN88106966A patent/CN1016962B/en not_active Expired
- 1988-08-12 KR KR1019880010295A patent/KR970004271B1/en not_active IP Right Cessation
- 1988-08-12 JP JP63201830A patent/JP2532599B2/en not_active Expired - Fee Related
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Also Published As
| Publication number | Publication date |
|---|---|
| MX169172B (en) | 1993-06-23 |
| DE3826801A1 (en) | 1989-02-23 |
| IT1226738B (en) | 1991-02-05 |
| JPH01133974A (en) | 1989-05-26 |
| KR970004271B1 (en) | 1997-03-26 |
| KR890004359A (en) | 1989-04-21 |
| IT8821706A0 (en) | 1988-08-12 |
| GB8818969D0 (en) | 1988-09-14 |
| GB2208644B (en) | 1991-11-13 |
| FR2619370A1 (en) | 1989-02-17 |
| GB2208644A (en) | 1989-04-12 |
| ES2006956A6 (en) | 1989-05-16 |
| CN1033977A (en) | 1989-07-19 |
| CN1016962B (en) | 1992-06-10 |
| JP2532599B2 (en) | 1996-09-11 |
| FR2619370B1 (en) | 1993-12-17 |
| IE61487B1 (en) | 1994-11-02 |
| HK994A (en) | 1994-01-14 |
| DE3826801C2 (en) | 2003-05-15 |
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