Lutetium oxide-based transparent ceramic scintillators

Patent metadata

Field	Value
Publication number	US-9238773-B2
Application number	US-201213623811-A
Country	US
Kind code	B2
Filing date	Sep 20, 2012
Priority date	Sep 22, 2011
Publication date	Jan 19, 2016
Grant date	Jan 19, 2016

Abstract

In one embodiment, a transparent ceramic of sintered nanoparticles includes gadolinium lutetium oxide doped with europium having a chemical composition (Lu 1-x Gd x ) 2-Y Eu Y O 3 , where X is any value within a range from about 0.05 to about 0.45 and Y is any value within a range from about 0.01 to about 0.2, and where the transparent ceramic exhibits a transparency characterized by a scatter coefficient of less than about 10%/cm. In another embodiment, a transparent ceramic scintillator of sintered nanoparticles, includes a body of sintered nanoparticles including gadolinium lutetium oxide doped with a rare earth activator (RE) having a chemical composition (Lu 1-x Gd x ) 2-Y RE Y O 3 , where RE is selected from the group consisting of: Sm, Eu, Tb, and Dy, where the transparent ceramic exhibits a transparency characterized by a scatter coefficient of less than about 10%/cm.

First claim

What is claimed is:

1. A transparent ceramic of sintered nanoparticles, the transparent ceramic comprising: gadolinium lutetium oxide doped with europium having a chemical composition (Lu 1-x Gd x ) 2-Y Eu Y O 3 ,
wherein X is any value within a range from about 0.05 to about 0.45,
wherein Y is any value within a range from about 0.01 to about 0.2,
wherein the transparent ceramic exhibits a transparency characterized by a scatter coefficient of less than about 10%/cm, and
wherein the transparent ceramic excludes monoclinic structures.

2. The transparent ceramic as recited in claim 1 , wherein the transparent ceramic is phase-pure.

3. The transparent ceramic as recited in claim 1 , wherein the transparent ceramic consists of a cubic crystal grain lattice.

4. The transparent ceramic as recited in claim 1 , wherein the transparent ceramic is characterized by a density of at least about 95%.

5. The transparent ceramic as recited in claim 1 ,
wherein the transparent ceramic is characterized by having substantially no residual porosity,
wherein the transparent ceramic consists essentially of grain structures being characterized by a cubic phase.

6. The transparent ceramic as recited in claim 1 , wherein the transparent ceramic is characterized by a thickness from about 20 μm to about 1000 μm and a diameter from about 0.2 cm to about 5 cm.

7. The transparent ceramic as recited in claim 1 , wherein the transparent ceramic is characterized by a thickness from about 1 mm to about 10 mm and a diameter from about 1 cm to about 35 cm.

8. The transparent ceramic as recited in claim 1 , wherein the transparent ceramic exhibits a transparency characterized by a scatter coefficient of less than about 5%/cm.

9. A method of forming the transparent ceramic as recited in claim 1 , the method comprising:
sintering powdered nanoparticles under a vacuum and at a temperature below a cubic-to-monoclinic phase temperature of the powdered nanoparticles until the sintered nanoparticles achieve a density of at least about 95%; and
pressurizing the sintered nanoparticles to a pressure of about 200 MPa in an atmosphere comprising an inert gas and using a hot-isostatic-pressing (HIP) process,
wherein the HIP process comprises heating the sintered nanoparticles to a temperature in a range from about 1750 C to about 1900 C, and
wherein the powdered nanoparticles comprise:
europium;
lutetium; and
gadolinium.

10. The transparent ceramic as recited in claim 1 , wherein the transparency is further characterized by a transmittance greater than about 75%.

11. A transparent ceramic scintillator of sintered nanoparticles, comprising:
a body comprising sintered nanoparticles comprising: gadolinium lutetium oxide doped with a rare earth activator (RE) having a chemical composition (Lu 1-x Gd x ) 2-Y RE Y O 3 ,
wherein RE is selected from the group consisting of: Sm, Eu, Tb, and Dy,
wherein X is any value within a range from about 0.05 to about 0.45, and
wherein Y is any value within a range from about 0.01 to about 0.2,
wherein the transparent ceramic exhibits a transparency characterized by a scatter coefficient of less than about 10%/cm, and
wherein the transparent ceramic excludes monoclinic structures.

12. The transparent ceramic as recited in claim 11 ,
wherein the transparent ceramic is characterized by having substantially no residual porosity,
wherein the transparent ceramic consists essentially of a cubic phase.

13. The transparent ceramic as recited in claim 11 , wherein the transparent ceramic is characterized by a thickness from about 20 μm to about 1000 μm and a diameter from about 0.2 cm to about 5 cm.

14. The transparent ceramic as recited in claim 11 , wherein the transparent ceramic is characterized by a thickness from about 1 mm to about 10 mm and a diameter from about 1 cm to about 35 cm.

15. The transparent ceramic as recited in claim 11 , wherein the transparent ceramic exhibits a transparency characterized by a scatter coefficient of less than about 5%/cm.

16. The transparent ceramic as recited in claim 11 , wherein the RE is selected from the group consisting of: Sm and Dy.

17. A method of forming the transparent ceramic as recited in claim 11 , comprising:
sintering powdered nanoparticles under a vacuum at a temperature below a cubic-to-monoclinic phase temperature of the powdered nanoparticles until the sintered nanoparticles achieve a density of at least about 95%; and
pressurizing the sintered nanoparticles to a pressure of about 200 MPa in an atmosphere comprising an inert gas and using a hot-isostatic-pressing (HIP) process,
wherein the HIP process comprises heating the sintered nanoparticles to a temperature in a range from about 1750 C to about 1900 C, and
wherein the powdered nanoparticles comprise:
RE;
Lu; and
Gd.

18. The transparent ceramic as recited in claim 11 , wherein the transparent ceramic is substantially devoid of residual porosity.

19. The transparent ceramic as recited in claim 11 , wherein the RE comprises at least two of the: Sm, Eu, Tb, and Dy.

20. A method, comprising:
using the transparent ceramic as recited in claim 11 to generate a radiographic image, wherein the transparent ceramic is an optical component of an imaging device selected from:
a synchrotron imaging apparatus;
an x-ray computed tomography apparatus; and
an x-ray imaging device.

Assignees

• L Livermore Nat Security Llc

Inventors

• Seeley Zachary
• Cherepy Nerine
• Kuntz Joshua
• Payne Stephen A

Classifications

• C09K11/7787 Primary

  Oxides (C09K11/7785 takes precedence) · CPC title

• C04B2235/77

  Density · CPC title

• C04B35/50

  based on rare-earth compounds {(non-oxide rare earth compounds C04B35/5156)} · CPC title

• C04B2235/608

  Green bodies or pre-forms with well-defined density · CPC title

• C04B2235/5409

  expressed by specific surface values · CPC title