NANO-SCALE METAL OXYHALIDE AND OXYSULFIDE SCINTILLATION MATERIALS AND METHODS FOR MAKING SAME

• US 20110024685A1
• Filed: 01/21/2010
• Published: 02/03/2011
• Est. Priority Date: 03/26/2007
• Status: Abandoned Application

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Srivastava, Alok, Stoklosa, Stanley John, Duclos, Steven Jude, Clothier, Brent Allen, Venkataramani, Venkat Subramaniam, Loureiro, Sergio Paulo Martins
• Application Number:
  US12/690,980
• Publication Number:
  US 20110024685A1
• Time in Patent Office: Days
• US Class Current: 252/301.4S
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01B 13/328 by processes making use of emulsions, e.g. the kerosine process
• CPC Class Codes: C01F 17/241 containing two or more rare earth metals, e.g. NdPrO3 or LaNdPrO3
• CPC Class Codes: C01F 17/253 Halides
• CPC Class Codes: C01F 17/259 Oxyhalides
• CPC Class Codes: C01F 17/294 Oxysulfides
• CPC Class Codes: C01G 1/06 Halides
• CPC Class Codes: C01G 1/12 Sulfides
• CPC Class Codes: C01P 2002/54 one element only
• CPC Class Codes: C01P 2004/64 Nanometer sized, i.e. from 1-100 nanometer

Abstract

Crystalline scintillator materials comprising nano-scale particles of metal oxides, metal oxyhalides and metal oxysulfides are provided. The nano-scale particles are less than 100 nm in size. Methods are provided for preparing the particles. In one method, used to form oxyhalides and oxysulfides, metal salts are dissolved in water, and then precipitated out as fine particles using an aqueous base. After the particles are separated from the solution, they are annealed under a flow of a water saturated hydrogen anion gas, such as HCl or H₂S, to form the crystalline scintillator particles The other methods take advantage of the characteristics of microemulsion solutions to control droplet size, and, thus, the particle size of the final nano-particles. For example, in one method, a first micro-emulsion containing metal salts if formed. The first micro-emulsion is mixed with an aqueous base in a second micro-emulsion to form the final nano-scale particles.

Claims

1-34. -34. (canceled)

35. A method for making nano-scale particles of an oxyhalide or oxysulfide type scintillation material, comprising:

adding an aqueous base to an aqueous solution comprising one or more metal salts to precipitate a gel containing the one or more metal salts;

removing free ions from the gel;

heating the gel; and

drying the gel to form the nano-scale particles of the oxyhalide or oxysulfide type scintillation material.

36. The method of claim 35 wherein the one or more metal salts comprise at least one metal anion selected from the group consisting of lanthanoids, group 2 elements, group 3 elements, group 13 elements, group 14 elements, group 15 elements, and combinations thereof.

37. The method of claim 35 wherein the one or more metal salts comprise at least one metal anion selected from the group consisting of lanthanum, cerium, terbium, thallium, gadolinium, europium, and combinations thereof.

38. The method of claim 35 wherein the aqueous base comprises NH4OH.

39. The method of claim 35 wherein drying the gel comprises heating the gel in a water-saturated atmosphere of an anion source gas.

40. The method of claim 35 wherein the anion source gas comprises at least one of H2S, HCl, HBr, HI, or HF.

41. The method of claim 35 wherein the oxyhalide or oxysulfide based scintillation material comprises a phosphor having a general formula of LaO(I, Br, Cl, or F):

Tb.

42. The method of claim 35 wherein the nano-scale particles of the oxyhalide or oxysulfide based scintillater material are less than about 100 nm in size.

43-57. -57. (canceled)