Patent ID: 6594100
Filing Date: 2003-07-15
Classification: C23C,G11B

Abstract:
A method for generating magnetized states in a region of a recording layer of a magnetic recording medium comprising:providing on the medium a magnetic recording layer comprising a first ferromagnetic film having a magnetic moment per unit area, a nonferromagnetic spacer film on the first ferromagnetic film, and a second ferromagnetic film having a magnetic moment per unit area different from the moment per unit area of the first ferromagnetic film and antiferromagnetically coupled to the first ferromagnetic film across the spacer film; applying to said recording layer region a magnetic field in a first direction in the plane of the layer to cause the moments of the first and second ferromagnetic films in said region to align substantially parallel to said first direction; reducing the magnetic field to said region to zero to cause the ferromagnetic film with the lesser moment in said region to flip its moment to be antiparallel to said first direction, thereby generating in said region a first magnetized state wherein the ferromagnetic film with the greater moment is oriented substantially parallel to said first direction in the absence of a magnetic field; thereafter applying to said region magnetized in said first state a magnetic field in a second direction in the plane of the layer and antiparallel to said first direction to cause the moments of the first and second ferromagnetic films in said region to align substantially parallel to said second direction; and reducing the magnetic field to said region to zero to cause the ferromagnetic film with the lesser moment in said region to flip its moment to be antiparallel to said second direction, thereby changing the magnetic state in said region to a second magnetized state wherein the ferromagnetic film with the greater moment is oriented substantially parallel to said second direction in the absence of a magnetic field.