Media Design and Orientation in Perpendicular Media

Author

Chureemart, J. ; Chureemart, P. ; Pressesky, J. ; Nolan, T. ; O´Grady, K.

Author_Institution

Dept. of Phys., Univ. of York, York, UK

Volume

49

Issue

7

fYear

2013

fDate

Jul-13

Firstpage

3592

Lastpage

3595

Abstract

The variation of coercivity as a function of angle has been used to characterise the distribution of easy axis orientation in various media structures. This technique removes the effect of the demagnetising field (H_D) due to the zero value of the magnetisation (M) at the coercivity. The orientation distribution has been investigated via comparison with the Stoner-Wohlfarth model. We find that exchange coupled composite (ECC) media, which have the grains almost completely segregated, fit the simulation with a standard deviation of the orientation distribution of 5°. The calculation does not fit the experimental results for granular and continuous granular composite (CGC) media due to exchange coupling between the grains. In-plane and cross-section transmission electron microscopy (TEM) analysis have been carried out to investigate the effect of silica segregation of the grains on the exchange coupling.

Keywords

coercive force; composite materials; demagnetisation; exchange interactions (electron); silicon compounds; transmission electron microscopy; SiO₂; Stoner-Wohlfarth model; TEM analysis; coercivity variation; continuous granular composite media; cross-section transmission electron microscopy; demagnetising field effect; easy axis orientation distribution; exchange coupled composite media; exchange coupling; grain silica segregation effect; in-plane transmission electron microscopy; magnetisation; media design; media structures; perpendicular media; Coercive force; Couplings; Magnetic hysteresis; Magnetic recording; Magnetometers; Media; Saturation magnetization; Distribution of easy axis orientation; exchanging coupling; switching field distribution (SFD);

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2013.2245109

Filename

6559260