Patent attributes
A magnetoresistance effect element has a first ferromagnetic metal layer, a second ferromagnetic metal layer, and a tunnel barrier layer that is sandwiched between the first and second ferromagnetic metal layers, and a tunnel barrier layer that is sandwiched between the first and second ferromagnetic metal layers, the tunnel barrier layer is expressed by a composition formula of AB2Ox (0<x≤4), and has a spinel structure in which cations are arranged in a disordered manner, the tunnel barrier layer has a lattice-matched portion and a lattice-mismatched portion, A is a divalent cation of plural non-magnetic elements, B is an aluminum ion, and in the composition formula, the number of the divalent cation is smaller than half the number of the aluminum ion.
