Träger für Datenspeicher und Verfahren zu seiner Herstellung.

摘要

A data storage medium for storing magnetically readable data has a substrate (16) with a substantially planar surface (18), a crystalline underlayer (20) deposited on the planar surface to a thickness within the range of from about 200 to 6000 Angstroms, and a crystalline recording layer (22) formed by epitaxial growth of a magnetic thin film upon the underlayer (20). The underlayer has a substantially uniform crystalographic orientation predetermined to control the orientation of crystals epitaxially grown upon the underlayer and the underlayer is comprised of individual grains having average diameters in the range of from about 100 to 1000 Angstroms. The crystalographic orientation of the recording layer is determined by the crystalographic orientation of the underlayer so that the axes of easy magnetisation of the crystals comprising the recording layer are substantially aligned in the plane parallel to the planar surface (18) and are comprised of individual grains in continuous and inter-connected interstitial regions between adjacent grains. Thus each grain is substantially isolated from its adjacent grains in order to reduce significantly exchange coupling inter-actions between neighbouring grains with the width of any one of the interstitial regions separating adjacent grains being at least three times the crystal lattice constant of the alloy comprised in the grains. The recording layer is formed with a thickness in the range of 300 to 1000 Angstroms. The underlayer (20) consists essentially of at least one of the following elements: chromium, molybdenum, tungsten, bismuth, niobium, tantalum, vanadium and titanium. The recording layer (22) consists essentially of one of the following alloys:- a) cobalt at up to 95 atomic percent, chromium at from 5 to 18 atomic percent, and a third component at from 1 to 20 atomic percent and consisting of at least one of the following elements: tungsten, tantalum, molybdenum, vanadium, niobium, platinum, bismuth, zirconium, and hafnium; b) cobalt at up to 93 atomic percent, nickel in the range of from 5 to 40 atomic percent and a third component from 2 to 20 atomic percent consisting essentially of at least one of the following elements: chromium, tantalum, tungsten, zirconium and platinum; and c) cobalt and from 2 to 35 atomic percent of a second component consisting essentially of at least one of the following elements: sumarium, yttrium, chromium, nickel, selenium and tungsten. ;