Critical thickness and orbital ordering in ultrathin La0.7Sr0.3MnO3 films
Critical thickness and orbital ordering in ultrathin La0.7Sr0.3MnO3 films
复制标题
DOI：
10.1103/physrevb.78.094413
复制
发表时间：
2008-09-01
影响因子：
3.7
通讯作者：
Ramesh, R.
中科院分区：
文献类型：
--
作者：
Huijben, M.;Martin, L. W.;Ramesh, R.
对厚度从3到70个单元格的La0.7Sr0.3MnO3超薄薄膜进行了详细的输运、磁性和x射线吸收光谱测量，结果表明，在只有3个单元格的SrTiO3（001）衬底界面处，非金属非铁磁性层的临界厚度较低（类似于12埃）。此外，线性二色性测量表明，对于所有层厚度，在没有任何轨道重建的情况下，存在优选的(x（2)-y(2)）面内轨道有序。对这些超薄膜进行精确研究的一个关键要求是控制生长过程，提供一层一层生长和块状磁性/输运特性的共存。
Detailed analysis of transport, magnetism, and x-ray absorption spectroscopy measurements on ultrathin La0.7Sr0.3MnO3 films with thicknesses from 3 to 70 unit cells resulted in the identification of a lower critical thickness for a nonmetallic nonferromagnetic layer at the interface with the SrTiO3 (001) substrate of only three unit cells (similar to 12 angstrom). Furthermore, linear-dichroism measurements demonstrate the presence of a preferred (x(2)-y(2)) in-plane orbital ordering for all layer thicknesses without any orbital reconstruction at the interface. A crucial requirement for the accurate study of these ultrathin films is a controlled growth process, offering the coexistence of layer-by-layer growth and bulklike magnetic/transport properties.