Patent · US Expired

Multi-layered anti-ferromagnetically coupled magnetic media

US6737172B1 · kind B1 · utility

4Cited by
11References
19Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 7, 2001
Grant dateMay 18, 2004
Priority date
Expiry dateDec 7, 2021

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T428/265
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

An anti-ferromagnetically coupled (“AFC”), high areal density magnetic recording medium having improved thermal stability and signal-to-medium noise ratio (“SMNR”), comprising:(a) a non-magnetic substrate having at least one surface; and(b) a ferromagnetic recording layer comprising a layer stack overlying the at least one surface, the layer stack comprising a plurality of vertically spaced-apart ferromagnetic layers, the ferromagnetic layers being spaced-apart by respective non-magnetic spacer layers providing anti-ferromagnetic coupling (AFC) therebetween, the total exchange energy acting upon each of the ferromagnetic layers of the layer stack in the remanent state and their effective magnetic energies adjusted to provide opposing alignment of the magnetic moments of adjacent ferromagnetic layers of the stack.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.