Abstract
Understanding the dynamic process of microwave-assisted magnetization reversal (MAMR) in a dipole-dipole coupled granular perpendicular medium is essential for its application to future magnetic storage devices. We experimentally investigated the magnetization reversal process in CoCrPt-SiO2 granular films in terms of the dependence of the switching field on the strength of an applied in-plane radio-frequency magnetic field. The reversal process changed from non-uniform rotation to uniform rotation when the frequency increased toward the ferromagnetic resonance frequency. In the resonant condition, the switching field agreed well with a model assuming uniform rotation of the magnetization in each grain. The agreement suggests that the decoherence of ferromagnetic resonance due to a dynamic dipolar field is weak in adequately exchange-coupled granular films with a saturation magnetization of 415 emu/cm3. This finding is significant for the development of the practical medium necessary for MAMR writing.
| Original language | English |
|---|---|
| Article number | 043915 |
| Journal | Journal of Applied Physics |
| Volume | 114 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - 2013 Jul 28 |
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ASJC Scopus subject areas
- Physics and Astronomy(all)
Cite this
Frequency dependence of critical switching asteroid of CoCrPt-SiO 2 granular film under 50-ns microwave impulse. / Ishida, N.; Soeno, Y.; Sekiguchi, K.; Nozaki, Yukio.
In: Journal of Applied Physics, Vol. 114, No. 4, 043915, 28.07.2013.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Frequency dependence of critical switching asteroid of CoCrPt-SiO 2 granular film under 50-ns microwave impulse
AU - Ishida, N.
AU - Soeno, Y.
AU - Sekiguchi, K.
AU - Nozaki, Yukio
PY - 2013/7/28
Y1 - 2013/7/28
N2 - Understanding the dynamic process of microwave-assisted magnetization reversal (MAMR) in a dipole-dipole coupled granular perpendicular medium is essential for its application to future magnetic storage devices. We experimentally investigated the magnetization reversal process in CoCrPt-SiO2 granular films in terms of the dependence of the switching field on the strength of an applied in-plane radio-frequency magnetic field. The reversal process changed from non-uniform rotation to uniform rotation when the frequency increased toward the ferromagnetic resonance frequency. In the resonant condition, the switching field agreed well with a model assuming uniform rotation of the magnetization in each grain. The agreement suggests that the decoherence of ferromagnetic resonance due to a dynamic dipolar field is weak in adequately exchange-coupled granular films with a saturation magnetization of 415 emu/cm3. This finding is significant for the development of the practical medium necessary for MAMR writing.
AB - Understanding the dynamic process of microwave-assisted magnetization reversal (MAMR) in a dipole-dipole coupled granular perpendicular medium is essential for its application to future magnetic storage devices. We experimentally investigated the magnetization reversal process in CoCrPt-SiO2 granular films in terms of the dependence of the switching field on the strength of an applied in-plane radio-frequency magnetic field. The reversal process changed from non-uniform rotation to uniform rotation when the frequency increased toward the ferromagnetic resonance frequency. In the resonant condition, the switching field agreed well with a model assuming uniform rotation of the magnetization in each grain. The agreement suggests that the decoherence of ferromagnetic resonance due to a dynamic dipolar field is weak in adequately exchange-coupled granular films with a saturation magnetization of 415 emu/cm3. This finding is significant for the development of the practical medium necessary for MAMR writing.
UR - http://www.scopus.com/inward/record.url?scp=84882370490&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84882370490&partnerID=8YFLogxK
U2 - 10.1063/1.4816778
DO - 10.1063/1.4816778
M3 - Article
AN - SCOPUS:84882370490
VL - 114
JO - Journal of Applied Physics
JF - Journal of Applied Physics
SN - 0021-8979
IS - 4
M1 - 043915
ER -