Ternary metal halide scintillators

Patent metadata

Field	Value
Publication number	US-2016168458-A1
Application number	US-201414906199-A
Country	US
Kind code	A1
Filing date	Jul 18, 2014
Priority date	Jul 19, 2013
Publication date	Jun 16, 2016
Grant date	—

Abstract

Metal halide scintillators are described. More particularly, the scintillators include doped (e.g., europium-doped) ternary metal halides, such as those of the formulas A 2 BX 4 and AB 2 X 5 , wherein A is an alkali metal, such as Li, Na, K, Rb, Cs or any combination thereof; B is an alkali earth metal, such as Be, Mg, Ca, Sr, Ba or any combination thereof; and X is a halide, such as Cl, Br, I, F or any combination thereof. Radiation detectors comprising the novel metal halide scintillators and other ternary metal halides, such as those of the formulas A 2 EuX 4 and AEu 2 X 5 , wherein A is an alkali metal and X is a halide, are also described.

First claim

1 . A scintillator material comprising one of Formulas (I), (III), (IV), (V), or (VI):
A 2 B (1-y) L y X 4   (I);
AB 2(1-y) L 2y X 5   (II);
A′ 2(1-y) L′ 2y BX 4   (III);
A′ (1-y) L′ y B 2 X 5   (IV);
A″ 2(1-y) L″ 2y BX 4   (V); or
A″ (1-y) L″ y B 2 X 5   (VI);

wherein:
0. 0001≦y≦5;
A is one or more alkali metal;
A′ is one or more of the group consisting of Li, K, Rb, and Cs;
A″ is Na or a combination of Na and one or more additional alkali metal;
B is one or more alkali earth metal;
L is selected from the group consisting of Eu, Ce, Tb, Yb, and Pr;
L′ is selected from the group consisting of Tl, In, and Na;
L″ is selected from the group consisting of Tl and In; and
X is one or more halide.

2 . The scintillator material of claim 1 , wherein A or A′ is selected from K, Rb, and Cs.

3 . The scintillator material of claim 1 , wherein B is selected from Sr and Ba.

4 . The scintillator material of claim 1 , wherein X is selected from Cl, Br, and I.

5 . The scintillator material of claim 1 , wherein L is Eu and the scintillator material comprises A 2 B (1-y) Eu y X 4 .

6 . The scintillator material of claim 1 , wherein 0.01≦y≦1.

7 . The scintillator material of claim 6 , wherein 0.025≦y≦0.05.

8 . The scintillator material of claim 7 , comprising A 2 B 0.95 Eu 0.05 X 4 .

9 . The scintillator material of claim 7 , wherein the scintillator material is selected from the group consisting of K 2 BaI 4 :Eu 5%; K 2 BaBr 4 :Eu 5%; Rb 2 BaCl 4 :Eu 5%; K 2 SrBr 4 :Eu 5%; and Rb 2 BaCl 4 :Eu 2.5%.

10 . A radiation detector comprising a photon detector and a scintillation material, wherein the scintillation material comprises a scintillator material of claim 1 .

11 . The radiation detector of claim 10 , wherein the detector is a medical diagnostic device, a device for oil exploration, or a device for container or baggage scanning.

12 . A method of detecting gamma rays, X-rays, cosmic rays, and/or particles having an energy of 1 keV or greater, the method comprising using the radiation detector of claim 10 .

13 . A radiation detector comprising a photon detector and a scintillation material, wherein the scintillation material comprises one of Formulas (I′), (III′), (IV′), (V′), or (VI′):
A 2 B (1-z) L z X 4   (I′);

A′ 2(1-z) L′ 2z BX 4   (III′);

A′ (1-z) L′ z B 2 X 5   (IV′);

A″ 2(1-z) L″ 2z BX 4   (V′); or

A″ (1-z) L″ z B 2 X 5   (VI′);

wherein:
0.0001≦z≦1.0;
A is one or more alkali metal;
A′ is one or more of the group consisting of Li, K, Rb, and Cs;
A″ is Na or a combination of Na and one or more additional alkali metal;
B is one or more alkali earth metal;
L is selected from the group consisting of Eu, Ce, Tb, Yb, and Pr;
L′ is selected from the group consisting of Tl, In, and Na;
L″ is selected from the group consisting of Tl and In; and
X is one or more halide.

14 . The radiation detector of claim 13 , wherein A or A′ is selected from K, Rb, and Cs.

15 . The radiation detector of claim 13 , wherein B is selected from Sr and Ba.

16 . The radiation detector of claim 13 , wherein X is selected from Cl, Br, and I.

17 . The radiation detector of claim 13 wherein L is Eu and the scintillator material comprises A 2 B (1-z) Eu z X 4 .

18 . The radiation detector of claim 13 , wherein

19 . The radiation detector of claim 13 , wherein 0.025≦z≦0.05.

20 . The radiation detector of claim 13 , wherein the scintillation material comprises A 2 B 0.95 Eu 0.05 X 4 .

21 . The radiation detector of claim 13 , wherein the scintillation material is selected from the group consisting of K 2 BaI 4 :Eu 5%; K 2 BaBr 4 :Eu 5%; Rb 2 BaCl 4 :Eu 5%; K 2 SrBr 4 :Eu 5%; and Rb 2 BaCl 4 :Eu 2.5%.

22 . The radiation detector of claim 13 , wherein z is 1.

23 . The radiation detector of claim 22 , wherein the scintillation material is K 2 EuCl 4 .

24 . The radiation detector of claim 13 , wherein the detector is a medical diagnostic device, a device for oil exploration, or a device for container or baggage scanning.

25 . A method of detecting gamma rays, X-rays, cosmic rays, and/or particles having an energy of 1 keV or greater, the method comprising using the radiation detector of claim 13 .

26 . A method of preparing a scintillator material of claim 1 , wherein the method comprises heating a mixture of raw materials above their respective melting temperatures.

27 . The method of claim 26 , wherein the method comprises:
(a) providing a mixture of raw materials, wherein the raw materials are provided in a stoichiometric ratio according to the formula of claim 1 ; (b) sealing said mixture in a sealed container; (c) heating the mixture to about 20° C. above the melting point of the raw material having the highest melting point for a period of time; (d) cooling the mixture to about room temperature; and (e) optionally repeating steps (c) and (d).

28 . The method of claim 26 , wherein the scintillator material is prepared in polycrystalline form.

29 . A scintillator material comprising Formula (II):
AB 2(1-y) L 2y X 5   (II),

wherein:
0.0001≦y≦0.5;
A is one or more alkali metal, optionally wherein A is selected from K, Rb, and Cs;
B is one or more alkali earth metal;
L is selected from the group consisting of Eu, Ce, Tb, Yb, and Pr; and
X is one or more halide selected from F, Cl, and Br, optionally wherein X is selected from Cl and Br.

30 . The scintillator material of claim 29 , wherein L is Eu and the scintillator material comprises AB 2(1-y) Eu 2y X 5 .

31 . The scintillator material of claim 29 , wherein 0.01≦y≦0.1; optionally wherein 0.025≦y≦0.05; optionally wherein the scintillator material comprises AB 2(0.975) Eu 2(0.025) X 5 ; optionally wherein the scintillator material is selected from the group consisting of RbSr 2 Cl 5 :Eu 2.5%; KSr 2 Br 5 :Eu 2.5%; RbBa 2 Br 5 :Eu 2.5%; and RbSr 2 Br 5 :Eu 2.5%.

32 . A scintillator material selected from the group consisting of KBa 2 I 5 :Eu 2.5%; CsSr 2 I 5 :Eu 2.5%; KSr 2 I 5 :Eu 4%; and KSr 2 I 5 :Eu 2.5%.

33 . A radiation detector comprising a photon detector and a scintillation material, wherein the scintillation material comprises Formula (II′):
AB 2(1-z) L 2z X 5   (II′),

wherein:
0.0001≦z≦1.0;
A is one or more alkali metal, optionally selected from K, Rb, and Cs;
B is one or more alkali earth metal;
L is selected from the group consisting of Eu, Ce, Tb, Yb, and Pr; and
X is one or more halide selected from the group F, Cl, and Br, optionally selected from Cl and Br.

34 . The radiation detector of claim 33 , wherein L is Eu and the scintillator material comprises AB 2(1-z) Eu 2z X 5 .

35 . The radiation detector of claim 33 , wherein the scintillation material comprises AB 2(0.975) Eu 2(0.025) X 5 , optionally wherein the scintillation material is selected from the group consisting of RbSr 2 Cl 5 :Eu 2.5%; KSr 2 Br 5 :Eu 2.5%; RbBa 2 Br 5 :Eu 2.5%; and RbSr 2 Br 5 :Eu 2.5%.

36 . The radiation detector of claim 33 , wherein the scintillation material is RbEu 2 Cl 5 .

37 . The scintillator material of claim 29 , wherein B is selected from Sr and Ba.

Assignees

• Univ Tennessee Res Foundation

Inventors

• Stand Luis
• Zhuravleva Mariya
• Melcher Charles L

Classifications

• G01T1/2006

  using a combination of a scintillator and photodetector which measures the means radiation intensity · CPC title

• G01T1/2023

  Selection of materials · CPC title

• C09K11/7733 Primary

  with alkali or alkaline earth metals · CPC title

• G01T1/20185

  Coupling means between the photodiode and the scintillator, e.g. optical couplings using adhesives with wavelength-shifting fibres · CPC title

• G21K2004/10

  with a protective film · CPC title