Magnetic memory

Abstract

Provided is a magnetic random access memory to which spin torque magnetization reversal is applied, the magnetic random access memory being thermal stable in a reading operation and also being capable of reducing a current in a wiring operation. A magnetoresistive effect element formed by sequentially stacking a fixed layer, a nonmagnetic barrier layer, and a recording layer is used as a memory element. The recording layer adopts a laminated ferrimagnetic structure. The magnetic memory satisfies the expression M(t/w)>|J|>(2kTΔ)/S, in which kis a Boltzmann constant, T is an operating temperature of the magnetic memory, S is an area parallel to a film surface of the magnetoresistive effect element, t and Mare respectively a film thickness and a saturated magnetization of the ferromagnetic layer having a smaller film thickness among two ferromagnetic layers which are constituent members of the laminated ferrimagnetic structure, w is a length of a short side of the recording layer, Δ is a thermal stability index of the magnetic memory, and Jis exchange coupling energy acting between the two ferromagnetic layers of the recording layer.