Magnetic recording media with dead magnetic layer
AssigneeWestern Digital Technologies, Inc.
InventorsCristian Papusoi, Kai Tang
Life of this patent
Estimating the term…
Abstract
A magnetic recording medium includes a rigid substrate, an amorphous soft magnetic underlayer (SUL) on the substrate, a dead magnetic layer on the SUL, a seed layer on the dead magnetic layer, and a magnetic recording layer (MRL) on the seed layer. The dead magnetic layer is configured to provide an interdiffusion region between the amorphous SUL and seed layer with a saturation magnetic moment per unit area less than 5×10−5 electromagnetic unit (emu)/cm2, and to produce a recording medium having an increase in tracks per inch (TPI) without significant reduction in bits per inch (BPI), and a net increase in areal density capacity (ADC) relative to a recoding medium that does not have the dead magnetic layer.
Claims25
A magnetic recording medium comprising:
- a rigid substrate;
- an amorphous soft magnetic underlayer (SUL) on the rigid substrate;
- a non-magnetic layer on the SUL, the non-magnetic layer comprising a thickness in a range of 4 to 12 Angstroms;
- a seed layer on the non-magnetic layer;
- and
- a magnetic recording layer (MRL) on the seed layer,
- wherein a material of the non-magnetic layer is diffused with both the amorphous SUL and the seed layer to provide an interdiffusion region with a saturation magnetic moment per unit area greater than zero electromagnetic unit (emu)/cm2 and less than 5×10−5 emu/cm2.
A method for fabricating magnetic recording media, comprising:
- providing a rigid substrate;
- providing an amorphous soft magnetic underlayer (SUL) on the rigid substrate;
- providing a non-magnetic layer comprising a thickness in a range of 4 to 12 Angstroms and comprising a refractory metal on the amorphous SUL;
- providing a seed layer on the non-magnetic layer;
- and
- providing one or more magnetic recording layers on the seed layer,
- wherein a material of the non-magnetic layer is diffused with both the amorphous SUL and the seed layer to provide an interdiffusion region with a saturation magnetic moment per unit area greater than zero electromagnetic unit (emu)/cm2 and less than 5×10−5 emu/cm2.
A magnetic recording medium comprising:
- a rigid substrate;
- an amorphous soft magnetic underlayer (SUL) on the rigid substrate;
- a non-magnetic layer consisting essentially of pure tungsten on the SUL;
- a seed layer on the non-magnetic layer;
- and
- a magnetic recording layer (MRL) on the seed layer,
- wherein the composition of the non-magnetic layer consisting essentially of pure tungsten is at least 95% tungsten and the pure tungsten of the non-magnetic layer is diffused with both the amorphous SUL and the seed layer to provide an interdiffusion region with a saturation magnetic moment per unit area greater than zero electromagnetic unit (emu)/cm2 and less than 5×10−5 emu/cm2.
Dependencies are inferred from the claim text.