Scintillator material, radiation detector, and method for producing scintillator material
Provided is a scintillator material that is excited by radiation rays to emit visible light. The scintillator material has a cristobalite structure obtained by crystallizing a part of silica. A fluorescent material SrI 2 :Eu 2+ is incorporated into the cristobalite structure to form a nanocomposite, and the cristobalite structure contains an alkali metal ion.
1 . A scintillator material that is excited by radiation to emit visible light, the scintillator material comprising:
a cristobalite structure obtained by crystallizing a part of silica,
wherein a fluorescent material SrI 2 :Eu 2+ is incorporated into the cristobalite structure to form a nanocomposite, and
the cristobalite structure contains an alkali metal ion.
2 . The scintillator material according to claim 1 ,
wherein the alkali metal ion is any one of Li + , Na + , K + , Rb + , and Cs + .
3 . The scintillator material according to claim 1 ,
wherein the alkali metal ion is contained at a ratio of 0.1 mol % to 10 mol % with respect to Si contained in the cristobalite structure.
4 . The scintillator material according to claim 1 ,
wherein the fluorescent material is contained in a form of a single crystal or a polycrystal.
5 . The scintillator material according to claim 1 ,
wherein the silica is a porous body in which voids are distributed from a surface to an inside thereof.
6 . The scintillator material according to claim 5 ,
wherein the porous body is an aggregate of amorphous SiO 2 particles having an average particle diameter (D50) of 2 μm to 50 μm.
7 . The scintillator material according to claim 6 ,
wherein the SiO 2 particles contain an alkali metal component.
8 . The scintillator material according to claim 5 ,
wherein Sr ions are contained at a ratio of 0.9 mol % to 15 mol %, I ions are contained at a ratio of 2.0 mol % to 40 mol %, and Eu ions are contained at a ratio of 0.1 mol % to 5.0 mol %, with respect to Si contained in the cristobalite structure.
9 . A radiation detector comprising:
the scintillator material according to claim 1 ; and
a light detection unit configured to detect a wavelength of 400 nm or more and 500 nm or less.
10 . A method for producing a scintillator material, the method comprising:
a powder preparation step of forming a raw material powder containing a fluorescent material SrI 2 :Eu 2+ and an alkali metal material;
a porous body formation step of forming silica that is a porous body in which voids are distributed from a surface to an inside thereof; and
a heat treatment step of bringing the porous body into contact with the raw material powder and performing a heat treatment.