Details

Autor(en) / Beteiligte

• Takahashi, Y
• Kadono, T
• Yamamoto, S
• Singh, V R
• Verma, V K
• Ishigami, K
• Shibata, G
• Harano, T
• Takeda, Y
• Okane, T
• Saitoh, Y
• Yamagami, H
• Takano, M
• Fujimori, A

Titel

Orbital magnetic moment and coercivity of Si O sub(2)-coated FePt nanoparticles studied by x-ray magnetic circular dichroism

Ist Teil von

• Physical review. B, Condensed matter and materials physics, 2014-07, Vol.90 (2)

Erscheinungsjahr

2014

Quelle

PROLA

Beschreibungen/Notizen

• (ProQuest: ... denotes formulae and/or non-USASCII text omitted)We have investigated the spin and orbital magnetic moments of Fe in FePt nanoparticles in the L1 sub(0)-ordered phase coated with Si O sub(2) by x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD) measurements at the Fe L sub(2,3) absorption edges. Using XMCD sum rules, we evaluated the ratio of the orbital magnetic moment (M sub(orb)) to the effective spin magnetic moment ... of Fe to be M sub(orb)/... = 0.08. This M sub(orb)/... value is comparable to the value (0.09) obtained for FePt nanoparticles prepared by gas phase condensation, and is larger than the values (~0.05) obtained for FePt thin films, indicating a high degree of L1 sub(0) order. The hysteretic behavior of the FePt component of the magnetization was measured by XMCD. The magnetic coercivity (Hc) was found to be as large as 1.8 T at room temperature, ~3 times larger than the thin film value and ~50 times larger than that of the gas phase condensed nanoparticles. The hysteresis curve is well explained by the Stoner-Wohlfarth model for noninteracting single-domain nanoparticles with the Hc distributed from 1 to 5 T.