In-plane anisotropy in thin-film media: physical origins of orientation ratio

Micromagnetic study of anisotropy sources in textured longitudinal media

“…I T IS WELL KNOWN that the circumferential texturing (grooves) in Co-alloy longitudinal recording media introduces a magnetic anisotropy, which is generally referred to as "orientation ratio" ( ) [1]. Experiments have demonstrated that the texturing causes preferential in-plane -axis alignment along the grooves, with a larger out-of-plane canting perpendicular to the grooves [2]- [4], stress anisotropy in the Cr underlayer and the Co magnetic layer [5], [6], and disruption of the magnetic coupling at the texture lines in the film [7], [8].…”

“…The energy density of the th grain generally includes Zeeman, crystalline anisotropy, magnetostatic, and interganular exchange terms [9]: (1) In addition, magnetoelastic energy may be inserted in the above equation. Parameters for the -axis distribution, stress anisotropy, groove spacing, and magnetic properties were all obtained from experiments.…”

Pulsed laser deposition of amorphous soft magnetic thin films for sensor applications

“…Amorphous thin films show excellent magnetic, magnetotransport and magnetoelastic properties and can be used as components of sensors and transducers [1][2][3]. Soft magnetic thin films and multilayers of different compositions can be prepared by various techniques, for example electrodeposition [4], molecular beam epitaxy and rfsputtering [5][6][7]. Recently soft magnetic amorphous thin films and granular films prepared by pulsed laser deposition (PLD) have been reported [8][9][10].…”

Crystallographic orientation of Cr in longitudinal recording media and its relation to magnetic anisotropy

“…This would also explain the increase in the OR values with an increase in density of mechanical texture lines. 1,4 For different Pt containing systems the stress or magnetostriction values are different, hence with different alloy compositions, the OR value could be slightly different.…”

“…Although the origin of OR is so far not clearly understood, interesting studies have been reported which are beneficial for the future development of magnetic recording. [1][2][3][4] The two possible main mechanisms, suggested for this in-plane magnetic anisotropy, are stress on the magnetic layer, 1 and the c-axis ͑Co͓0002͔ direction͒ preference of orientation along the groove direction. 2,3 However, there are no explanations for this particular predominant c-axis orientation of the Co grains in the magnetic layer along the mechanical groove direction.…”