Please use this identifier to cite or link to this item:
|Title:||The effect of capped layer thickness on switching behavior in perpendicular CoCrPt based coupled granular/continuous media|
|Authors:||Li, W.M. |
Switching field distribution
|Citation:||Li, W.M., Lim, W.K., Shi, J.Z., Ding, J. (2013-08). The effect of capped layer thickness on switching behavior in perpendicular CoCrPt based coupled granular/continuous media. Journal of Magnetism and Magnetic Materials 340 : 50-56. ScholarBank@NUS Repository. https://doi.org/10.1016/j.jmmm.2013.03.021|
|Abstract:||A systematic investigation of magnetic switching behavior of CoCrPt based capped media (perpendicularly coupled granular/continuous (CGC) media consisting of granular CoCrPt:SiO2TiO2Ta2O 5/capped CoCrPt(B)) is performed by varying the thickness of the capped layer from 0 to 9 nm. The microscopic structures of CGC media with different thickness of capped layer are examined by transmission electron microscope. We find out that CoCrPt magnetic grains are separated by nonmagnetic oxide grain boundaries. Grain size and grain boundary are about 8.9 nm and 2 nm, respectively. The nonmagnetic oxide grain boundaries in the granular layer do not disappear immediately at the interface between the granular and capped layers. The amorphous grain boundary phase in the granular layer propagates to the top surface of the capped layer. After capping with the CoCrPt(B) layer, the grain size at the surface of CGC structure increases and the grain boundary decreases. Both coercivity and intergranular exchange coupling of the CGC media are investigated by Polar magneto-optic Kerr effect magnetometer and alternating gradient force magnetometer. Although Hc apparently decreases at thicker capped layer, no obvious variation of macroscopic switching field distribution (SFD/Hc) is observed. We separate intrinsic switching field distribution from intergranular interactions. The investigation of reduced intrinsic SFD/Hc and increased hysteresis loop slope at coercivity, suggests that improvement of absolute switching field distribution (SFD) is caused by both strong intergranular exchange coupling and uniform grain size. Micromagnetic simulation results further verify our conclusion that the capped layer in CGC media is not uniformly continuous but has some granular nature. However, grains in the CoCrPt(B) capped layer is not absolutely isolated, strong exchange coupling exists between grains. © 2013 Elsevier B.V.|
|Source Title:||Journal of Magnetism and Magnetic Materials|
|Appears in Collections:||Staff Publications|
Show full item record
Files in This Item:
There are no files associated with this item.
checked on Nov 13, 2018
WEB OF SCIENCETM
checked on Nov 7, 2018
checked on Sep 28, 2018
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.