Spectroscopic evidence for competing reconstructions in polar multilayers LaAlO3/LaVO3/LaAlO3.
Spectroscopic evidence for competing reconstructions in polar multilayers LaAlO3/LaVO3/LaAlO3.
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DOI：
10.1103/physrevlett.102.236401
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发表时间：
2009-06
影响因子：
8.6
通讯作者：
M. Takizawa;Y. Hotta;T. Susaki;Y. Ishida;H. Wadati;Y. Takata;K. Horiba;M. Matsunami;S. Shin;M. Yabashi;K. Tamasaku;Y. Nishino;T. Ishikawa;A. Fujimori;H. Hwang
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文献类型：
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作者：
M. Takizawa;Y. Hotta;T. Susaki;Y. Ishida;H. Wadati;Y. Takata;K. Horiba;M. Matsunami;S. Shin;M. Yabashi;K. Tamasaku;Y. Nishino;T. Ishikawa;A. Fujimori;H. Hwang
用芯能级光电子能谱研究了生长在SrTiO_3（001）衬底上的LaAlO（3）/LaVO（3）/LaAlO（3）三层薄膜中V的价态再分布。我们已经发现，V价是V3+和V4+之间的中间薄LaAlO 3盖层，随着盖层厚度的增加而减少，并最终恢复体积值V3+在约10单位电池厚度。为了解释这些结果，我们建议，原子重建的极性LaAlO 3表面的竞争与纯电子的V价变化，使极性灾难是避免在成本最低的能量。
We have studied the valence redistribution of V in LaAlO(3)/LaVO(3)/LaAlO(3) trilayers, which are composed of only polar layers grown on SrTiO3 (001) substrates, by core-level photoemission spectroscopy. We have found that the V valence is intermediate between V3+ and V4+ for thin LaAlO3 cap layers, decreases with increasing cap-layer thickness, and finally recovers the bulk value of V3+ at approximately 10 unit-cell thickness. In order to interpret these results, we propose that the atomic reconstruction of the polar LaAlO3 surface competes with the purely electronic V valence change so that the polar catastrophe is avoided at the cost of minimum energy.