US3257327A - Process for growing neodymium doped single crystal divalent metal ion tungstates - Google Patents

Process for growing neodymium doped single crystal divalent metal ion tungstates Download PDF

Info

Publication number
US3257327A
US3257327A US192723A US19272362A US3257327A US 3257327 A US3257327 A US 3257327A US 192723 A US192723 A US 192723A US 19272362 A US19272362 A US 19272362A US 3257327 A US3257327 A US 3257327A
Authority
US
United States
Prior art keywords
ion
melt
tungstate
atom percent
ions
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.)
Expired - Lifetime
Application number
US192723A
Other languages
English (en)
Inventor
Nassau Kurt
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
AT&T Corp
Original Assignee
Bell Telephone Laboratories Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority to NL292372D priority Critical patent/NL292372A/xx
Priority to BE631924D priority patent/BE631924A/xx
Application filed by Bell Telephone Laboratories Inc filed Critical Bell Telephone Laboratories Inc
Priority to US192723A priority patent/US3257327A/en
Priority to DEW34381A priority patent/DE1276012B/de
Priority to GB17308/63A priority patent/GB1033975A/en
Priority to FR934024A priority patent/FR1356173A/fr
Application granted granted Critical
Publication of US3257327A publication Critical patent/US3257327A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B15/00—Single-crystal growth by pulling from a melt, e.g. Czochralski method
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
    • C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
    • C09K11/77—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals
    • C09K11/7708—Vanadates; Chromates; Molybdates; Tungstates
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
    • C30B29/10—Inorganic compounds or compositions
    • C30B29/16—Oxides
    • C30B29/22—Complex oxides
    • C30B29/32—Titanates; Germanates; Molybdates; Tungstates
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/14—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range characterised by the material used as the active medium
    • H01S3/16—Solid materials
    • H01S3/1601—Solid materials characterised by an active (lasing) ion
    • H01S3/1603—Solid materials characterised by an active (lasing) ion rare earth
    • H01S3/1611—Solid materials characterised by an active (lasing) ion rare earth neodymium
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/14—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range characterised by the material used as the active medium
    • H01S3/16—Solid materials
    • H01S3/163—Solid materials characterised by a crystal matrix
    • H01S3/1675—Solid materials characterised by a crystal matrix titanate, germanate, molybdate, tungstate
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S117/00—Single-crystal, oriented-crystal, and epitaxy growth processes; non-coating apparatus therefor
    • Y10S117/918—Single-crystal waveguide

Definitions

  • One of the more promising maser devices is that which utilizes .as the active material a diamagnetic crystal convice utilizing neodymium-containing calcium tungstate a divalent metal-ion tungstate containing various trivalent rare earth ions.
  • the tungstate crystals are conveniently made by a method described as the CZochr-alski method. This method is described in an article by l. Czochralski in Zeitschrifit iii-r :Physikalische Chemie, volume 92, pages A recent description of the process is found in an article by K. Nassau and L. G. Van Uitert in Journal of Applied Physics, volume 31, page 1508 (1960).
  • a melt is formed of a mixture of initial ingredients, the composition of the melt controlling the composition of the grown crystal.
  • a seed crystal is inserted into the melt and simultaneously rotated and slowly withdrawn therefrom,
  • melt must contain one atom percent neodymium, based on the calcium ions present, in order to grow a crystal containing only 0.24 atom percent neodymium.
  • the absorption and emission spectra for trivalent rare earth ions in melt grown tungstates is not simple. from the present of a trivolent ion in a divalent lattice.
  • Calcium tungstate doped with neodymium has a plurality of fluorescent lines in the 0.8 to 1.4 micron region.
  • melt grown crystals An additional disadvantage of these melt grown crystals is the limited number of input signal frequencies capable of being amplified. For a minimum power input to produce maser action, each trivalent rare earth ion emits energy in only one primary line. Since the number of trivalent rare earth ions possessing the requisite characteristics necessary for maser operation is "limited, such ions being generally restricted to those having atomic numbers 58-60, 62, and 6471, the number of input signal (frequencies capable of being amplified is also limited.
  • the divalent metal-ion tungstates of the invention are calcium tungstate, strontium tungstate and barium tungstate, each having a noncubic crystalline lattice structure of the Scheelite type. From about 0.01 atom percent to 15 atom percent of the divalent ions are replaced by trivalent rare earth ions asthe active maser material, the ions having atomic numbers 58-60, 62 and 64-71. Enhanced maser operation is dependent upon further incorporating in the crystal monovalent ions.
  • the monovalent ions useful for enhancing maser operation are sodium, lithium and potassium;
  • mixture of the desired divalent metal-ion tungstate or a divalent metal-ion compound that reacts with tungstic acid anhydride to form the tungstate, at least one trivalent rare-earth ion-containing substance having the desired rare-earth ions and at least one monovalent ioncontaining substance having the desired monovalent ions, is heated to a temperature suflicient to form a molten solution.
  • a seed crystal is inserted into the melt and slowly withdrawn therefrom, crystal growth being thereby promoted on the seed crystal.
  • the efficacy of the process is dependent upon the use of a critical amount of monovalent ion in the melt.
  • the melt contains from 1.5 to 15 monovalent ions per trivalent ion in the melt with a maximum excess being attained when the melt contains 30 atom percent monovalent ion based on the number of divalent metal-ions present.
  • Tungstate crystals grown by the method of the invention are found to be particularly suitable for maser use and to possess enhanced maser characteristics.
  • the distribution coefficient of the trivalent rare earth ions in the melt compared to the ions incorporated into the crystal is greatly improved.
  • the use of the critical amount of excess monovalent ion in the melt results, for calcium tungstate crystals doped with neodymium, in the incorporation in the crystal of 0.83 atom percent neodymium when the melt contains one atom percent neodymium.
  • FIG. 1 on coordinates of relative emission intensity and Wavelength in microns is a plot showing the fluorescent line spectrum of a calcium tungstate crystal grown from a melt containing 8 atom percent sodium and 8 atom percent neodymium, the resulting crystal containing 2 atom percent neodymium.
  • FIG. 2 on coordinates of relative emission intensity and wavelength in microns is a plot showing the fluorescent line spectrum of a calcium tungstate crystal grown from a melt containing 10 atom percent sodium and 2.5 atom percent neodymium, the resulting crystal containing 2 atom percent neodymium.
  • FIG. 1 depicts the fluorescent line spectrum of a tungstate crystal grown from a melt containing one monovalent ion per trivalent rare earth ion. Crystals grown from melts containing no monovalent ion or less than one monovalent ion per trivalent rare earth ion exhibit similar spectra.
  • FIG. 2 depicts the spectrum of tungstate crystals grown from a melt containing four monovalent ions per trivalent rare earth ion. Crystals grown from melts containing 1.5 to monovalent ions per trivalent rare earth ion exhibit similar spectra.
  • Still another advantage accruing to the materials of the invention is an increase in intensity of the emitting lines.
  • Such increase is illustrative by a comparison of the emission intensity of a second fluorescent line, line 4, exhibited by the sodium-containing tungstate of this invention of FIG. 2, with a second fluorescent line, line 2, of the usual sodium-containing tungstate of FIG. 1.
  • the fluorescent line associated with the tungstate of the invention has a relative emission intensity of 60 percent of the most intense line
  • the equivalent fluorescent line associated with the tungstate of FIG. 1 has a relative emission intensity of only 50 percent of the most intense line.
  • a comparison of the figures shows that such increase is due to minimization of other fluorescent lines by the incorporated sodium ions in the amount indicated.
  • a further advantage accruing to many materials of the invention is also illustrated by the preceding comparison of relative emission intensities.
  • a first fluorescent line, line '3, at approximately 1.064 microns is observed under one joule of input power and a second fluorescent line, at approximately 1.065 microns, line 4, is observed under six joules of input power.
  • the crystal of FIG. 1 requires three joules of power for the first line, at approximately 1.065 microns, line '1, and eighteen joule-s of power for the next line, at approximately 1.066 microns, line 2.
  • the minimum power, or threshold, required to produce emission is significantly lower than that required for conventional crystals grown by the prior art technique.
  • the divalent metal ion tungstate may be introduced into the initial mixture as either the tungstate per se or as a compound such as a divalent metal-ion salt, oxide, nitrate or carbonate that will react with tungstic acid anhydride to form the tungstate.
  • a compound other than a tungstate it is preferable that the by-products of the reaction volatize during the subsequent heating step.
  • the only critical requirement is that such by-product does not act as a contaminant during growth of the tungstate crystal.
  • a stoichiometric amount of the divalent metal-ion compound and tungstic acid anhydride is utilized.
  • deviations from the stoichiometry are permissible, such deviations being generally limited to an excess or deficiency of divalent metal ions in the order of 5 atom percent due to the tendency of second phase formation in the growing crystal for greater deviations.
  • the trivalent rare earth ions and monovalent ions may also be introduced into the initial mixture in the form of compounds such as oxides, carbonates, salts or nitrates that, under the processing conditions, form a melt with the tungstate.
  • the concentration of monovalent ions in the melt necessary to achieve the desired concentration in the crystal is critical. It has been determined that the melt must contain at least 1.5 monovalent ions
  • Monovalent alkali ions suitable for practicing the invention are sodium, lithium and potassium.
  • the use of rubidium and cesium ions are precluded in the method because of their large ionic radii which introduces strain into the tungstate crystalline lattice.
  • the non rare-earth ion impurity limit is not critical.
  • the amount of accidentally added trivalent rare-earth ion impurity should not exceed 0.1 the amount of the principal active trivalent rare-earth ion intentionally added.
  • Ordinary reagent grade chemicals were used in the following specific examples and are suitable as the trivalent rare-earth ion impurity limits.
  • the above initial reactants are heated to a temperature sufiicient to form a molten solution.
  • This effect is readily determined visually.
  • a typical initial mixture of calcium tungstate, 2.2 atom percent neodymium and 11 atom percent sodium requires a temperature of approximately 1550 C. to form a molten solution.
  • the mixtures of the invention melt at temperatures in the order of 1525 C. to 1625 C.
  • a crucible made of an inert material such as rhodium or iridium is used to hold the initial mixture and the resulting melt during processing.
  • the atmosphere in which the heating is carried out is not critical. However, it is well known to use an inert or oxygen-containing atmosphere to prevent an ion in a higher valency state from being reduced to a lower valency state. For example, the tungsten ion, W+ is reduced to the lower valency state, W+ when a reducing atmosphere is used in conjunction with the elevated temperatures.
  • a seed crystal is inserted into the melt and slowly withdrawn therefrom.
  • the composition of the seed crystal- is not critical.
  • the composition may range from undoped to heavily doped tungstate crystals.
  • the seed crystal is generally slowly rotated while being withdrawn from the melt when uniformity of crystal growth is desired on all surfaces of the seed crystal.
  • pulling rate of approximately one-half inch per hour and .a rotation rate of 60 r.p.m. are convenient in the obtaining of large crystals. Other pulling rates are equally feasible, however, although it has been found that the growing crystal has a tendency to crack when rates substantially in excess of four inches per hour are utilized.
  • Example 1 100 grams CaWO 1.3 grams Nd O 2.7 grams W0 and 5.6 grams Na WO were initially mixed together. The mixture was then heated in a rhodium crucible in air to a temperature of 150 C. to form a molten solution. The solution contained 4 sodium ions per neodymium ion. A seed crystal of calcium tungstate was then inserted into the melt and simultaneously rotated and withdrawn from the melt. The rotation rate was approximately 60 rpm. and the pulling rate was approximately one-half inch per hour. The resulting calcium tungstate crystal contained approximately two atom percent neodymium.
  • Example 2 100 grams CaWO 0.2 gram Ce (WO and 0.55 gram Li WO were initially mixed together. The mixture was then heated in an iridium crucible in air to a temperature of 1600 C. to form a molten solution. The solution contained 10 lithium ions per cerium ion. A seed crystal of calcium tungstate was then inserted into the melt and simultaneously rotated at rpm. and withdrawn from the melt at two inches per hour. The resulting calcium tungstate crystal contained approximately 0.1 atom percent cerium.
  • Example 3 100 grams SrWO 2.1 grams NaTm(WO and 3.6 grams Na WO were initially mixed together. The mixture was then heated in a rhodium crucible in air to a temperature of 1580 C. to form a molten solution. The solution contained 5 sodium ions per thulium ion. A seed crystal of strontium tungstate'was then inserted into the melt and withdrawn therefrom at one-half inch per hour. The resulting strontium tungstate crystal contained approximately one atom percent thulium.
  • a process for growing single crystals of calcium tungstate comprising forming a mixture of initial ingredients equivalent to CaWO together with a trivalent neodymium ion-containing substance containing from about 0.01 atom percent to 18 atom percent based on the total calcium ions present of neodymium ion and a monovalent sodium ion-containing substance containing from about 1.5 sodium ions to 15 sodium ions per neodymium ion present, up to a maximum of 30 atom percent based on the total calcium ions present, heating said initial ingredients to a temperature sufiicien-t to form a molten solution, inserting a seed crystal into said molten solution and slowly withdrawing said seed crystal from said solution, thereby promoting crystal growth on said seed crystal.
  • neodymium-containing substance contains from about 0.1 to 4.0 atom percent of neodymium.
  • Nassau et a1. Preparation of Large Calcium-Tungstate Crystals Containing Paramagnetic Ions for Maser Applications, J. App. Phys, vol. 31, #8, August 1960, page 1508.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Metallurgy (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)
  • Inorganic Compounds Of Heavy Metals (AREA)
US192723A 1962-05-07 1962-05-07 Process for growing neodymium doped single crystal divalent metal ion tungstates Expired - Lifetime US3257327A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
NL292372D NL292372A (en, 2012) 1962-05-07
BE631924D BE631924A (en, 2012) 1962-05-07
US192723A US3257327A (en) 1962-05-07 1962-05-07 Process for growing neodymium doped single crystal divalent metal ion tungstates
DEW34381A DE1276012B (de) 1962-05-07 1963-04-29 Verfahren zum Zuechten von mit paramagnetischen Ionen dotierten Einkristallen aus Wolframaten der Erdalkalimetalle Calcium, Strontium oder Barium
GB17308/63A GB1033975A (en) 1962-05-07 1963-05-02 Improvements in or relating to the growth of single crystals of divalent metal ion tungstates
FR934024A FR1356173A (fr) 1962-05-07 1963-05-07 Procédé de croissance de tungstates monocristallins

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US192723A US3257327A (en) 1962-05-07 1962-05-07 Process for growing neodymium doped single crystal divalent metal ion tungstates

Publications (1)

Publication Number Publication Date
US3257327A true US3257327A (en) 1966-06-21

Family

ID=22710802

Family Applications (1)

Application Number Title Priority Date Filing Date
US192723A Expired - Lifetime US3257327A (en) 1962-05-07 1962-05-07 Process for growing neodymium doped single crystal divalent metal ion tungstates

Country Status (5)

Country Link
US (1) US3257327A (en, 2012)
BE (1) BE631924A (en, 2012)
DE (1) DE1276012B (en, 2012)
GB (1) GB1033975A (en, 2012)
NL (1) NL292372A (en, 2012)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3374444A (en) * 1964-10-21 1968-03-19 Du Pont Vacancy compensated calcium neodymium vanadate phosphors
US3375464A (en) * 1964-05-14 1968-03-26 Du Pont Single-phase, solid solution luminescent compositions, preparation thereof and lasers containing same
US3420780A (en) * 1962-08-10 1969-01-07 Comp Generale Electricite Process for removing the colour from oriented monocrystals
US3427566A (en) * 1964-03-02 1969-02-11 Union Carbide Corp Solid state laser device using gadolinium oxide as the host material
US3459667A (en) * 1964-02-26 1969-08-05 Rca Corp Phosphor and method of preparation thereof
US3488292A (en) * 1967-02-16 1970-01-06 Westinghouse Electric Corp Alkaline-earth metal pyrophosphate phosphors
US3502590A (en) * 1967-03-01 1970-03-24 Rca Corp Process for preparing phosphor
US3515675A (en) * 1966-12-27 1970-06-02 Lockheed Aircraft Corp Method for making luminescent materials
EP2727975A4 (en) * 2011-06-28 2014-12-31 Oceans King Lighting Science CERDED MAGNESIUM BARIUM WOLFRAMAT LUMINESCENCE THIN LAYER, METHOD OF MANUFACTURE AND APPLICATION

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2954300A (en) * 1958-10-31 1960-09-27 Ibm Method of preparation of single crystal ferroelectrics
US3003112A (en) * 1959-05-25 1961-10-03 Bell Telephone Labor Inc Process for growing and apparatus for utilizing paramagnetic crystals
US3053635A (en) * 1960-09-26 1962-09-11 Clevite Corp Method of growing silicon carbide crystals

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2954300A (en) * 1958-10-31 1960-09-27 Ibm Method of preparation of single crystal ferroelectrics
US3003112A (en) * 1959-05-25 1961-10-03 Bell Telephone Labor Inc Process for growing and apparatus for utilizing paramagnetic crystals
US3053635A (en) * 1960-09-26 1962-09-11 Clevite Corp Method of growing silicon carbide crystals

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3420780A (en) * 1962-08-10 1969-01-07 Comp Generale Electricite Process for removing the colour from oriented monocrystals
US3459667A (en) * 1964-02-26 1969-08-05 Rca Corp Phosphor and method of preparation thereof
US3427566A (en) * 1964-03-02 1969-02-11 Union Carbide Corp Solid state laser device using gadolinium oxide as the host material
US3375464A (en) * 1964-05-14 1968-03-26 Du Pont Single-phase, solid solution luminescent compositions, preparation thereof and lasers containing same
US3374444A (en) * 1964-10-21 1968-03-19 Du Pont Vacancy compensated calcium neodymium vanadate phosphors
US3515675A (en) * 1966-12-27 1970-06-02 Lockheed Aircraft Corp Method for making luminescent materials
US3488292A (en) * 1967-02-16 1970-01-06 Westinghouse Electric Corp Alkaline-earth metal pyrophosphate phosphors
US3502590A (en) * 1967-03-01 1970-03-24 Rca Corp Process for preparing phosphor
EP2727975A4 (en) * 2011-06-28 2014-12-31 Oceans King Lighting Science CERDED MAGNESIUM BARIUM WOLFRAMAT LUMINESCENCE THIN LAYER, METHOD OF MANUFACTURE AND APPLICATION
US9270084B2 (en) 2011-06-28 2016-02-23 Ocean's King Lighting Science & Technology Co., Ltd. Cerium doped magnesium barium tungstate luminescent thin film, manufacturing method and application thereof

Also Published As

Publication number Publication date
DE1276012B (de) 1968-08-29
BE631924A (en, 2012) 1900-01-01
NL292372A (en, 2012) 1900-01-01
GB1033975A (en) 1966-06-22

Similar Documents

Publication Publication Date Title
Wickersheim et al. Luminescent behavior of the rare earths in yttrium oxide and related hosts
Palilla et al. Rare earth activated phosphors based on yttrium orthovanadate and related compounds
Linares Growth and properties of CeO2 and ThO2 single crystals
KR102087857B1 (ko) 발광 중심의 섬광 응답을 단축시키는 방법 및 단축된 섬광 응답을 갖는 신틸레이터 물질
USRE26184E (en) Van ultert
Sibley et al. Effect of lead on the room-temperature colorability of KCl
Anderson Tb 3+ as a recombination center in ZnS
US3257327A (en) Process for growing neodymium doped single crystal divalent metal ion tungstates
JPH06169128A (ja) 固体非半導体レーザの製造方法
Tachibana et al. Distribution coefficient of rare-earth dopants in Y3Al5O12 garnet
Sekita et al. Strong Tb3+ emission of TbAlO3 at room temperature
US3203899A (en) Manufacture of materials capable of amplifying wave energy
US3462707A (en) Nd and yb doped borate laser glass
US3338841A (en) Luminescent molybdate and tungstate compositions
Thoma et al. EPR and luminescence studies of LaF3 and CeF3 under X-ray and laser irradiation
US3405371A (en) Fluorescent garnet compositions and optical maser devices utilizing such compositions
US3243723A (en) Optical maser using single crystal molybdate composition
EP0637861A1 (en) Infrared light-excited light-emitting substance
US3177154A (en) Optical maser crystals
US3375465A (en) Alkali compensated rare earth doped zinc or cadmium borate phosphors
Radhakrishnan et al. Photoluminescence of undoped and Eu doped CsCl crystals
Sharp et al. Energy Transfer and Fluorescence Quenching in Eu‐and Nd‐Doped Silicate Glasses
US3459667A (en) Phosphor and method of preparation thereof
Rubin et al. Preparation and fabrication of molybdate single crystals for optical maser studies
US3174938A (en) Optical maser crystals