US2447927A - Luminescent zinc fluoride - Google Patents

Luminescent zinc fluoride Download PDF

Info

Publication number
US2447927A
US2447927A US622823A US62282345A US2447927A US 2447927 A US2447927 A US 2447927A US 622823 A US622823 A US 622823A US 62282345 A US62282345 A US 62282345A US 2447927 A US2447927 A US 2447927A
Authority
US
United States
Prior art keywords
zinc fluoride
columbium
phosphor
zinc
activator
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
US622823A
Inventor
Ferd E Williams
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.)
RCA Corp
Original Assignee
RCA Corp
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
Application filed by RCA Corp filed Critical RCA Corp
Priority to US622823A priority Critical patent/US2447927A/en
Application granted granted Critical
Publication of US2447927A publication Critical patent/US2447927A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • C09K11/67—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing refractory metals
    • C09K11/674—Halogenides

Definitions

  • This invention relates to materials capable of fluorescing under excitation of agents, such as cathode rays, with a relatively long decay rate in luminescence when the excitation is removed.
  • Another object is to provide a phosphor ci zinc fluoride with an activator capable of varying the decay rate.
  • Zinc fiuoride with manganese activator has been found to be particularly efficient in radar and similar' uses because of its characteristic decay rate. The luminescence continues for a sufficient time to satisfactorily show the trace of moving objects and then blanks out suddenly. Such a phosphor is disclosed in the application of Maggio Banca, filed April 19, 1945, Serial No. 589,269.
  • curve I shows the decay characteristic of the zinc fluoride phosphor when 0.0008 gram mole of columbium activator is used Number to each gram mole of Zinc fluoride.
  • Curve 2 shows the ch-aracteristic with 0.03 gram mole of columbium per gram mole of zinc fluoride. It will be apparent that wide control of the decay rate can be obtained by varying the columbium content.
  • the phosphor may be prepared by adding C. P. concentrated hydroiluoric acid to zinc oxide and columbium of the desired content, either as a salt such as CbSO4x(OH)y, or as a metal.
  • CbSO4x(OH)y a salt
  • metallic columbium preferably in powder form, is preferred, as the sulphate or other anion decreases the efciency of the phosphor.
  • the materials, after thorough mixing, are evaporated to dryness by heating for about onehalf hour at from 500 C. to 900 C. in a relatively neutral atmosphere.
  • the columbium activator is thought to exist in the iluorde crystal lattice as the oxide and not as the fluoride, since the latter boils at 229 C.
  • a phosphor consisting of zinc fluoride and an activator of columbium having a gram mole ratio to the zinc fluoride of substantially 0.0008 to 1.
  • a phosphor consisting of zinc fiuoride and columbium activator in the ratio of 0.0008 to 0.03 gram mole of columbium to one gram mole of zinc uoride.

Description

Aug. 24, 1948.` F. E. WILLIAMS )2,447,927
LUMINESCENT ZINC FLUORIDE Filed oct. 17, 1945 Patented Aug. 24, 1948 UNITED LUMINESCENT ZINC FLUORIDE Ferd E. Williams, Princeton, N. J., assignor to Radio Corporation of America, a corporation of Delaware Application October 17, 1945, Serial No. 622,823
2 Claims. l
This invention relates to materials capable of fluorescing under excitation of agents, such as cathode rays, with a relatively long decay rate in luminescence when the excitation is removed.
In phosphore of the type disclosed, the intensity of luminescence is given by the equation I=At*", where A is a constant depending upon the particular ingredients and excitation intensity, t is time and n is a variable also dependent upon the ingredients of the mixture, particularly the activator used.
It is an object of this invention to provide a phosphor of good eicency and a relatively slow decay rate.
Another object is to provide a phosphor ci zinc fluoride with an activator capable of varying the decay rate.
Other objects of the invention will appear in the following specification, reference being had to the drawing, in which the single gure of the drawing contains graphs illustrating the performance of the improvement, the abscissas representing time in seconds in linear scale and the ordinates representing intensity of luminescence in logarithmic scale.
Zinc fiuoride with manganese activator has been found to be particularly efficient in radar and similar' uses because of its characteristic decay rate. The luminescence continues for a sufficient time to satisfactorily show the trace of moving objects and then blanks out suddenly. Such a phosphor is disclosed in the application of Maggio Banca, filed April 19, 1945, Serial No. 589,269.
I have found that zinc fluoride, when activated by columb-ium (also known as niobium), has a quitebroad spectrum with a peak at 4700 and that n in the equation ILAt-7L can be varied from 0.8 to 1.2 by increasing the columbium gram mole content from ZnF2:0.0008 Cby to ZnFz:0.03Cb. This control of the decay is an important ad- Vantage.
In the drawing, curve I shows the decay characteristic of the zinc fluoride phosphor when 0.0008 gram mole of columbium activator is used Number to each gram mole of Zinc fluoride. Curve 2 shows the ch-aracteristic with 0.03 gram mole of columbium per gram mole of zinc fluoride. It will be apparent that wide control of the decay rate can be obtained by varying the columbium content.
The phosphor may be prepared by adding C. P. concentrated hydroiluoric acid to zinc oxide and columbium of the desired content, either as a salt such as CbSO4x(OH)y, or as a metal. However, the use of metallic columbium, preferably in powder form, is preferred, as the sulphate or other anion decreases the efciency of the phosphor. The materials, after thorough mixing, are evaporated to dryness by heating for about onehalf hour at from 500 C. to 900 C. in a relatively neutral atmosphere.
The columbium activator is thought to exist in the iluorde crystal lattice as the oxide and not as the fluoride, since the latter boils at 229 C.
Having described my invention, what I claim 1s:
1. A phosphor consisting of zinc fluoride and an activator of columbium having a gram mole ratio to the zinc fluoride of substantially 0.0008 to 1.
2. A phosphor consisting of zinc fiuoride and columbium activator in the ratio of 0.0008 to 0.03 gram mole of columbium to one gram mole of zinc uoride.
FERD E. WILLIAMS.
REFERENCES CITED The following references are of record in the iile of this patent:
UNITED STATES PATENTS Name Date Fischer Aug. 4, 1936 McKeag Dec. 24 1940 CTI-IER REFERENCES Chem. Abstracts, vol. 18, page 2287.
US622823A 1945-10-17 1945-10-17 Luminescent zinc fluoride Expired - Lifetime US2447927A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US622823A US2447927A (en) 1945-10-17 1945-10-17 Luminescent zinc fluoride

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US622823A US2447927A (en) 1945-10-17 1945-10-17 Luminescent zinc fluoride

Publications (1)

Publication Number Publication Date
US2447927A true US2447927A (en) 1948-08-24

Family

ID=24495647

Family Applications (1)

Application Number Title Priority Date Filing Date
US622823A Expired - Lifetime US2447927A (en) 1945-10-17 1945-10-17 Luminescent zinc fluoride

Country Status (1)

Country Link
US (1) US2447927A (en)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2049765A (en) * 1932-05-09 1936-08-04 Fischer Hellmuth Luminescent glass and method of making same
US2226407A (en) * 1938-03-16 1940-12-24 Gen Electric Luminescent material

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2049765A (en) * 1932-05-09 1936-08-04 Fischer Hellmuth Luminescent glass and method of making same
US2226407A (en) * 1938-03-16 1940-12-24 Gen Electric Luminescent material

Similar Documents

Publication Publication Date Title
US2447322A (en) Infrared-responsive phosphors
GB1336053A (en) Luminescent materials
US2485903A (en) Vii type phosphor
US2447927A (en) Luminescent zinc fluoride
US2402759A (en) Method of manufacturing luminescent material
US2447447A (en) Phosphor materials
US2126233A (en) Luminescent composition and method of making the same
US2614082A (en) Zinc sulfide type phosphors containing magnesium sulfide
US2601032A (en) Manganese activated zinc barium silicate phosphor
GB1271388A (en) Method of making phosphors
US2802792A (en) Electroluminescent phosphors
US2615849A (en) Infrared quenchable zinc sulfide phosphors
US2558532A (en) Cathode-ray screen coated with zinc or magnesium fluoride phosphors
US4315190A (en) Zinc silicate phosphor with extended florescence decay and cathode ray tube containing the same
US4069061A (en) Ceramics having nonlinear voltage characteristics
US2965512A (en) Zinc pyrophosphate treated sulfide phosphors and their preparation
US2474506A (en) Method of making phosphor materials
US2727866A (en) Phosphor containing gallium
US2447449A (en) Phosphor material
GB747439A (en) Activated-lanthanum oxychloride phosphors
US2947704A (en) Luminescent zinc sulfide phosphors and the preparation thereof
US2470627A (en) Phosphor
US2736712A (en) Luminescent magnesium oxide
US2482450A (en) Barium halophosphate phosphor
US4122370A (en) Cathode ray tube containing a manganese activated rare earth fluoride luminescent material