Quantum splitting oxide phosphor and method of making

• US 5,571,451 A
• Filed: 01/03/1995
• Issued: 11/05/1996
• Est. Priority Date: 01/03/1995
• Status: Expired due to Fees

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Beers, William W., Srivastava, Alok M.
• Primary Examiner(s): KOSLOW, CAROL M
• Application Number:
  US08/367,637
• Time in Patent Office: 672 Days
• Field of Search: 252/301.4 R, 423/600, 423/263, 501/127, 501/153, 501/152, 501/120, 313/486
• US Class Current: 252/301.40R
• CPC Class Codes: C04B 35/01 based on oxide ceramics
• CPC Class Codes: C04B 35/44 based on aluminates
• CPC Class Codes: C09K 11/7706 Aluminates
• CPC Class Codes: C09K 11/778 Borates

Abstract

A quantum splitting oxide phosphor is described for use with VUV radiation. The oxide material has an atomic ratio, comprising: Sr_1-X Pr_X Al_12-X Mg_X O₁₉ ; where 0<X≦0.20. The material is stable and compatible for use as a phosphor with VUV radiation created by Hg vapor discharge.

Claims

1. An oxide phosphor comprising Sr, Al and Mg as constituents of the oxide, having an oxide lattice that is doped with Pr⁺³, said oxide phosphor adapted to exhibit quantum splitting behavior in the oxide lattice when irradiated by a source of VUV radiation.

7. The oxide phosphor of claim 1, wherein the oxide comprises a composition represented by Sr_1-X Pr_X Al_12-X Mg_X O₁₉, where 0<

X≦

0.20.

8. The oxide phosphor of claim 1, wherein the VUV radiation results from a Hg vapor discharge in the presence of the oxide phosphor.

2. A method of making Sr_1-X Pr_X Al_12-X Mg_X O₁₉ material that exhibits quantum splitting behavior, where 0<

X≦

0.20, comprising the steps of;

selecting a value of X so as to define a composition;

forming a substantially homogeneous mixture from a quantity of each of the compounds SrCO₃, Pr₆ O₁₁, Al(OH)₃ and MgO that is sufficient to satisfy a stoichiometric requirement of the composition; and

firing the mixture in a non-oxidizing atmosphere at a temperature and for a time sufficient to sinter the mixture and form a material having a composition comprising Sr_1-X Pr_X Al_12-X Mg_X O₁₉, where 0<

X≦

0.20, and Pr is in a state as Pr³⁺, wherein the material exhibits quantum splitting behavior when excited by VUV radiation.

3. The method of claim 2, wherein the non-oxidizing atmosphere is a forming gas atmosphere.

4. A lamp comprising an evacuated housing, a VUV radiation source located within the housing, and a phosphor that is located within the housing and adapted to be excited by the VUV radiation source, said phosphor comprising an oxide of aluminum, strontium, praseodymium and magnesium that exhibits quantum splitting when excited by VUV radiation.

5. The lamp of claim 4, wherein the phosphor comprises Sr_1-X Pr_X Al_12-X Mg_X O₁₉, where 0<

X≦

0.20.

6. The lamp of claim 5, wherein the VUV radiation source is Hg that is adapted to be excited by an excitation means so as to create an Hg vapor discharge.