MAGNETORESISTIVE MEMORY WITH LOW CRITICAL CURRENT FOR MAGNETIZATION SWITCHING

摘要

A magnetoresistive memory element comprising a magnetic tunnel junction or magnetic multilayer exhibiting giant magnetoresistance with a free magnetic layer made of a material that is prone to a spin reorientation transition driven by lattice strains and/or surface magnetocrystalline anisotropy allows a significant reduction of the threshold current density needed for magnetization switching in a spin-transfer torque MRAM. Strained free layers made of a ferromagnet with weak cubic magnetocrystalline anisotropy and a high magnetostriction and ultrathin free layers with an appropriate surface magnetocrystalline anisotropy and thickness lead to particularly strong effects.