Patent ID: 8228059

Claim:
A ferrite material having a composition gradient for measuring magneto-optical effect properties comprising a composition gradient ferrite thin film which has a gradient in the horizontal direction on a single crystal substrate having a light transmitting property, wherein the composition gradient ferrite thin film is formed of a multilayer film of composition gradient ferrite layers inclined in the horizontal direction of the single crystal substrate, a thickness of each composition gradient ferrite layer is 0.8 to 4.5 nm, and a thickness of said multilayer film is 30 to 10000 nm, the ferrite is spinel ferrite or Y-type hexagonal ferrite which are characterized by the following general formulae respectively, spinel ferrite general formula: A 1-x B x Fe 2 O 4 (0.00≦x≦1.00) wherein, A and B are respectively one, two or more kinds of elements selected from the group consisting of Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mg, Al, Ga and In and A≠B; Y-type hexagonal ferrite general formula: A 2 (B1 x B2 y )Fe 12 O 22 (0.00≦x≦2.00, 0.00≦y≦2.00, x+y=2.00) wherein, A is Ba and/or Sr, and B1 and B2 are respectively one, two or more kinds of elements selected from the group consisting of Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mg, Al, Ga and In and B1≠B2; and the single crystal substrate is a MgAl 2 O 4 (111) substrate.