Fluorescent material, scintillator using same, and radiation detector using same

A fluorescent material for a scintillator having a garnet structure, the material comprising:

• Ce, Gd, Ga, Al, O, Fe, and a component M;
• wherein Ce acts as an activator;
• wherein:
• 24.3≦Gd concentration (mass %)≦57.6,
• 0≦Lu concentration (mass %)≦31.1,
• 0.02.ltoreq.Ce concentration (mass %).ltoreq.0.7,
• 4.0≦Al concentration (mass %)≦12.8,
• 7.5≦Ga concentration (mass %)≦22.6,
• 0≦Sc concentration (mass %)≦2.64,
• 19.6≦O concentration (mass %)≦22.8,
• 0.05≦Fe concentration (mass ppm)≦1, and
• 0≦M concentration (mass ppm)≦50;
• wherein the component M is at least one of Mg, Ti, and Ni;
• and wherein the sum of all the elements is set at 100 mass %.

A fluorescent material for a scintillator having a garnet structure, the material comprising:

• Ce, Gd, Ga, Al, O, Fe, and a component M;
• wherein Ce acts as an activator,
• wherein:
• 45.9≦Gd concentration (mass %)≦52.8,
• 1.7≦Lu concentration (mass %)≦12.0,
• 0.06≦Ce concentration (mass %)≦0.24,
• 7.0≦Al concentration (mass %)≦10.0,
• 13.7≦Ga concentration (mass %)≦20.6,
• 0.05≦Sc concentration (mass %)≦0.5,
• 20.75≦O concentration (mass %)≦21.9,
• 0.05≦Fe concentration (mass ppm)≦0.4, and
• 3.1≦M concentration (mass ppm)≦15;
• wherein the component M is at least one of Mg, Ti, and Ni, and wherein the sum of all the elements is set at 100 mass %.

A fluorescent material comprising:

• Ce, the Ce acting as an activator;
• at least Gd, Al, Ga, O, Fe, and
• a component Lu and/or Y;
• wherein the fluorescent material contains not more than 3 weight % of Fe of the content of Ce in a fluorescent material having a garnet structure expressed by the general formula:
• (Gd1-x-zLxCez)3+a(Al1-uGau)5−aO12
• wherein L is Lu and/or Y,
• 0≦a≦0.15,
• 0≦x≦1.0,
• 0.0003≦z≦0.0167,
• (x +z ≦1.0), and
• 0.2≦u≦0.6.