In situ resonant photoemission characterization of La0.6Sr0.4MnO3 layers buried in insulating perovskite oxides
In situ resonant photoemission characterization of La0.6Sr0.4MnO3 layers buried in insulating perovskite oxides
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DOI：
10.1063/1.2163827
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发表时间：
2006-04
影响因子：
3.2
通讯作者：
H. Kumigashira;R. Hashimoto;A. Chikamatsu;M. Oshima;T. Ohnishi;M. Lippmaa;H. Wadati;A. Fujimori;K. Ono;M. Kawasaki;H. Koinuma
中科院分区：
文献类型：
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作者：
H. Kumigashira;R. Hashimoto;A. Chikamatsu;M. Oshima;T. Ohnishi;M. Lippmaa;H. Wadati;A. Fujimori;K. Ono;M. Kawasaki;H. Koinuma
我们用Mn2p-3D共振光电子能谱研究了SrTiO_3(STO)/La0.6Sr0.4MnO_3(LSMO)异质界面和LSMO薄膜中的Mn3d偏态密度。在Mn2p-3d阈值下，Mn3d光谱的强烈增强使我们能够提取与STO覆盖层界面附近的LSMO层的m3d光谱。我们发现，当↑膜被STO覆盖时，费米能级附近的Eg-LSMO态的光谱强度显著降低。STO/LSMO界面和空穴掺杂LSMO薄膜的Eg↑态强度降低的相似性表明，空穴掺杂在靠近STO层的LSMO层中起源于由Ti02-SRO-MnO2-La0.6Sr0.4O-组成的价失配界面的化学载流子浓度调制，这对于基于钙钛矿氧化物的多层膜来说是不可避免的。
We have investigated the Mn 3d partial density of states in SrTiO3(STO)∕La0.6Sr0.4MnO3(LSMO) heterointerfaces as well as of LSMO films using Mn 2p-3d resonant photoemission spectroscopy. The strong enhancement of the Mn 3d spectra at the Mn 2p-3d threshold enables us to extract the Mn 3d spectra of LSMO layers in the vicinity of the interface with the STO overlayers. We have found that the spectral intensity of eg↑ states near the Fermi level is drastically reduced when the LSMO film is capped with STO overlayers. The close similarity in reduction of the intensity of the eg↑ states between the STO/LSMO interface and hole-doped LSMO films suggests that the hole doping into the LSMO layer close to the STO layer originates from the chemical carrier-concentration modulation at the valence-mismatched interface composed of the stacking sequence -TiO2-SrO-MnO2-La0.6Sr0.4O-, which is inevitable for multilayers based on perovskite oxides.