Magnetic switching volumes of CoSm thin films for high density longitudinal recording

Abstract

Abstraci -For a high density recording media, the magnetic switching volume is of great importance when considering media noise and thermal stability. CoSdCr films have been prepad and the influence of the Cr underlayer thickness and of the magnetic layer preparation conditions on the magnetic switching volume have been investigated through magnetic viscosity and remnance curve measurements. The measured switching volumes ranged from 3.0 to 15.2x10-'*cm3, and implications regarding noise and thermal stability are discussed.

Effect of CrRu underlayer on the magnetic, recording, and thermal stability characteristics of CoCrPtTa thin film media

“…Publisher Item Identifier S 0018-9464(00)08383-7. force magnetometer (AGFM) [6], [7]. The crystallographic orientation and lattice constants were characterized by X-ray diffraction using standardscans with Cu radiation.…”

Magnetic Media, Magnetization Reversal

“…Recently, changes in coercivity with field sweep rate have become important in the design of high-density recording media (20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32). Analysis of time-dependent phenomena treats magnetic media as consisting of an assembly of single-domain particles having magnetic anisotropy energy K and switching volume V. K represents the tendency of magnetization to lie along an ''easy axis,'' and V is the volume of the particle that needs to switch its magnetization to initiate reversal of the magnetization direction in Magnetization (emu)…”

“…However, in CoSm deposited on a Cr underlayer (29), the switching volume was similar to the Cr The model was developed originally for particulate media such as iron oxide or ferrite particles, but has more recently grain size and considerably larger than the CoSm crystal size, and in CoCrPt/Cr the switching volume was also found (24,26,28,30) been applied to thin-film media, for which the assumption of noninteracting particles is even less justifiable. to be considerably larger than grain size (27).…”

Transmission Electron Microscopy Study of Magnetic Domain of Cobalt-Samarium Thin Films Fabricated Using DC Magnetron Sputtering Technique

“…Some recording experiments have been investigated, for example, by Velu and Lambeth [4] and Velu et al [5]. However, the growth characteristics of CoSm alloys including the concentration range [6], the epitaxial relation between CoSm alloy films and underlayer materials [7], interaction effects [8], and the magnetic switching volume [9] suggest that improved magnetic properties of CoSm films could be obtained by utilization and optimisation of appropriate deposition conditions. It is well known that magnetic properties of thin magnetic layers have predominantly affected by several parameters such as preparation conditions, films fabrication methods and utilization of underlayer materials.…”