Patent ID: 7465502
Filing Date: 2008-12-16
Classification: G11B

Abstract:
1. A magnetic recording medium, comprising: a hard magnetic recording layer; and a metamagnetic layer magnetically exchange coupled to the hard magnetic recording layer, wherein the metamagnetic layer has a characteristic of magnetic field induced reversible transitioning from an antiferromagnetic state to a ferromagnetic state when it is subject to an external applied magnetic field applied in ambient operating temperatures without any applied external heating to assist in magnetic recording, wherein the initial state of the metamagnetic layer at ambient temperature and no externally applied magnetic field (H=0) is the antiferromagnetic (AFM) state and the reversible transition to the ferromagnetic (FM) state occurs at an H less than that required to reverse the magnetization direction of the hard magnetic recording layer prior to the AFM to FM transition in the metamagnetic layer, and wherein after the AFM to FM transition the metamagnetic layer effectively lowers the coercivity of the hard magnetic recording layer to permit data recording by the externally applied magnetic field.