Patent ID: 7785490

Claim:
A Pr-doped inorganic compound, containing a solid solution having been formed by substitution of at least a part of at least one kind of substitutable ions, which are contained at a substitutable ion site in a matrix oxide, by Pr, the Pr-doped inorganic compound satisfying the condition represented by the formula: 0.91r2≦r1≦1.05r2 wherein r 1 represents the mean ionic radius of ionic radiuses of all of elements, including Pr, which elements constitute the substitutable ion site having been doped with Pr, and r 2 represents the ionic radius of Pr; and wherein the Pr-doped inorganic compound is a garnet type compound, which may be represented by General Formula (1): (Al 3-x-y A2 x Pr y )B 2 C 3 O 12 (1) wherein A 1 represents La, A 2 represents Sc, B represents Sc, C represents Ga, x represents a number satisfying the condition 0≦x<0.25, y represents a number satisfying the condition 0<y≦3, provided that 0<x+y≦3, and O represents the oxygen atom.