TY - JOUR
T1 - Magnetic characteristics and nanostructures of FePt granular films with GeO2 segregant
AU - Ono, Takuya
AU - Moriya, Tomohiro
AU - Hatayama, Masatoshi
AU - Tsumura, Kaoru
AU - Kikuchi, Nobuaki
AU - Okamoto, Satoshi
AU - Kitakami, Osamu
AU - Shimatsu, Takehito
N1 - Publisher Copyright:
© 2017 Author(s).
PY - 2017/1/9
Y1 - 2017/1/9
N2 - To realize a granular film composed of L10-FePt grains with high uniaxial magnetic anisotropy energy, Ku, and segregants for energy-assisted magnetic recording, a FePt-GeO2/FePt-C stacked film was investigated in the engineering process. The FePt-GeO2/FePt-C stacked film fabricated at a substrate temperature of 450 °C realized uniaxial magnetic anisotropy, Kugrain, of about 2.5 × 107erg/cm3, which is normalized by the volume fraction of FePt grains, and a granular structure with an averaged grain size of 7.7 nm. As the thickness of the FePt-GeO2 upper layer was increased to 9 nm, the Ku values were almost constant. That result differs absolutely from the thickness dependences of the other oxide segregant materials such as SiO2 and TiO2. Such differences on the oxide segregant are attributed to their chemical bond. The strong covalent bond of GeO2 is expected to result in high Ku of the FePt-GeO2/FePt-C stacked films.
AB - To realize a granular film composed of L10-FePt grains with high uniaxial magnetic anisotropy energy, Ku, and segregants for energy-assisted magnetic recording, a FePt-GeO2/FePt-C stacked film was investigated in the engineering process. The FePt-GeO2/FePt-C stacked film fabricated at a substrate temperature of 450 °C realized uniaxial magnetic anisotropy, Kugrain, of about 2.5 × 107erg/cm3, which is normalized by the volume fraction of FePt grains, and a granular structure with an averaged grain size of 7.7 nm. As the thickness of the FePt-GeO2 upper layer was increased to 9 nm, the Ku values were almost constant. That result differs absolutely from the thickness dependences of the other oxide segregant materials such as SiO2 and TiO2. Such differences on the oxide segregant are attributed to their chemical bond. The strong covalent bond of GeO2 is expected to result in high Ku of the FePt-GeO2/FePt-C stacked films.
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U2 - 10.1063/1.4973473
DO - 10.1063/1.4973473
M3 - Article
AN - SCOPUS:85009186325
VL - 110
JO - Applied Physics Letters
JF - Applied Physics Letters
SN - 0003-6951
IS - 2
M1 - 022402
ER -