论文标题
PT上超薄钴铁氧体膜的生长和表征（111）
Growth and characterization of ultrathin cobalt ferrite films on Pt(111)
论文作者
论文摘要
COFE2O4薄膜（5 nm和20 nm厚）通过氧辅助分子束在PT上（111）在523〜K处生长，然后在真空或氧气中以773 K退火。它们使用螺旋钻电子光谱，低能电子衍射，扫描隧道显微镜和转换电子Mössbauer光谱进行表征。生长的薄膜由小的纳米颗粒组成。膜的退火产生了晶粒尺寸的增加，并在室温下产生了磁性，尽管膜的一小部分仍处于顺磁状态。退火还将钴分离诱导到较厚膜的表面。在低温下测得的Mössbauer光谱指示钴铁素体，这两种薄膜都显示出非常相似的高精细图案。在氧气或真空中退火影响了阳离子分布，在氧气中退火的情况下，阳离子分布更接近偏尖旋抗的预期。
CoFe2O4 thin films (5 nm and 20 nm thick) were grown by oxygen assisted molecular beam epitaxy on Pt(111) at 523~K and subsequently annealed at 773 K in vacuum or oxygen. They were characterized in-situ using Auger Electron Spectroscopy, Low-Energy Electron Diffraction, Scanning Tunneling Microscopy and Conversion Electron Mössbauer Spectroscopy. The as-grown films were composed of small, nanometric grains. Annealing of the films produced an increase in the grain size and gave rise to magnetic order at room temperature, although with a fraction of the films remaining in the paramagnetic state. Annealing also induced cobalt segregation to the surface of the thicker films. The measured Mössbauer spectra at low temperature were indicative of cobalt ferrite, the both films showing very similar hyperfine patterns. Annealing in oxygen or vacuum affected the cationic distribution, which was closer to that expected for an inverse spinel in the case of annealing in an oxygen atmosphere.
