TRANSPARENT FERROMAGNETIC ALKALI CHALCOGENIDE COMPOUND FOR SOLID-SOLVING TRANSITION METAL OR RARE EA

PROBLEM TO BE SOLVED : To provide a ferromagnetic alkali chalcogen compound capable of obtaining transparent ferromagnetic property which is completely spin-polarized by using an alkali chalcogen compound transmitting a light, and to provide a method of adjusting the ferromagnetic property thereof. SOLUTION : In the ferromagnetic alkali chalcogenide compound having ferromagnetic property, at least one kind of metal is selected from among a 3d transition metal element of Ti, V, Cr, Mn, Fe, Co, Ni or Cu; a 4d transition metal element of Zr, Nb, Mo, Tc, Ru or Rh; and a 5d transition metal element of Hf, Ta, W, Os, Re or Ir, or a lanthanum system rare earth element of Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu, to form a solid solution with the alkali chalcogenide compound having an inverse fluorite structure. Valence electron control is performed by adjusting the concentration of these metal elements, combining two or more metal elements, or adding an acceptor or a donor to adjust the ferromagnetic characteristic thereof.