TRANSPARENT FERROMAGNETIC ALKALI/CHALCOGENIDE COMPOUND COMPRISING SOLID SOLUTION OF TRANSITION METAL

A transparent ferromagnetic alkali/chalcogen compound providing ferromagnetism, which results from complete spin polarization of an alkali/chalcogen compound capable of light transmission; and a method of regulating the ferromagnetic properties thereof. In particular, a transparent ferromagnetic alkali/chalcogenide compound comprising a solid solution of at least one metal selected from among 3d transition metal elements including Ti, V, Cr, Mn, Fe, Co, Ni and Cu, 4d transition metal elements including Zr. Nb, Mo, Tc, Ru and Rh, 5d transition metal elements including Hf, Ta, W, Os, Re and Ir and lanthanum series rare earth elements including Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu in an alkali/chalcogen compound having an inverted fluorite structure so as to exhibit ferromagnetic properties. The ferromagnetic properties thereof are regulated by effecting valence electron control through adjusting of the concentration of such metal elements, combination of two or more metal elements, addition of acceptor and donor, etc.