TY - JOUR
T1 - Film thickness and temperature dependence of the magnetic properties of pulsed-laser-deposited Fe3O4 films on different substrates
AU - Kale, Sangeeta
AU - Bhagat, S. M.
AU - Lofland, S. E.
AU - Scabarozi, T.
AU - Ogale, S. B.
AU - Orozco, A.
AU - Shinde, S. R.
AU - Venkatesan, T.
AU - Hannoyer, B.
AU - Mercey, B.
AU - Prellier, W.
PY - 2001/11/15
Y1 - 2001/11/15
N2 - We report a systematic study of <100> epitaxial films of magnetite (Fe3O4) of thickness 300-2000 Å, grown on single-crystal substrates (MgO, MgAl2O4, and SrTiO3) using pulsed laser deposition. The magnetic state was explored by measuring magnetization, conversion-electron Mössbauer spectroscopy, and ferromagnetic resonance. At 300 K, films grown on MgAl2O4 and SrTiO3 are, more or less, normal for all thicknesses. That is, the in-plane anisotropy is fourfold. The films on MgO, however, show no in-plane anisotropy if the thickness is less than ∼800 Å. In contrast to some previous claims, the present films exhibit magnetic saturation at quite modest (≤2 kOe) fields. We propose simple models to account for a variety of observations. In addition to the shape anisotropy, strains appear to play the major role in determining the variation of the magnetic behavior with thickness, substrate, and temperature.
AB - We report a systematic study of <100> epitaxial films of magnetite (Fe3O4) of thickness 300-2000 Å, grown on single-crystal substrates (MgO, MgAl2O4, and SrTiO3) using pulsed laser deposition. The magnetic state was explored by measuring magnetization, conversion-electron Mössbauer spectroscopy, and ferromagnetic resonance. At 300 K, films grown on MgAl2O4 and SrTiO3 are, more or less, normal for all thicknesses. That is, the in-plane anisotropy is fourfold. The films on MgO, however, show no in-plane anisotropy if the thickness is less than ∼800 Å. In contrast to some previous claims, the present films exhibit magnetic saturation at quite modest (≤2 kOe) fields. We propose simple models to account for a variety of observations. In addition to the shape anisotropy, strains appear to play the major role in determining the variation of the magnetic behavior with thickness, substrate, and temperature.
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M3 - Article
AN - SCOPUS:0035891124
SN - 0163-1829
VL - 64
SP - 2054131
EP - 2054139
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 20
M1 - 205413
ER -