Exploring possible ferromagnetism of the LaAlO3/SrTiO3 interface
Exploring possible ferromagnetism of the LaAlO3/SrTiO3 interface
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DOI：
10.1103/physrevmaterials.3.104418
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发表时间：
2019-10
影响因子：
3.4
通讯作者：
Pascal Wittlich;H. Boschker;T. Asaba;Lu Li;H. Noad;C. Watson;K. Moler;D. Daraselia;D. Japaridze;A. Shengelaya;Jianqiang Wang;J. Xia;J. Mannhart
中科院分区：
文献类型：
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作者：
Pascal Wittlich;H. Boschker;T. Asaba;Lu Li;H. Noad;C. Watson;K. Moler;D. Daraselia;D. Japaridze;A. Shengelaya;Jianqiang Wang;J. Xia;J. Mannhart
我们报告了n型LaAlO3/SrTiO3界面的广泛磁性研究，利用局部和综合分析技术：扫描超导量子干涉装置显微镜，极性Kerr磁强计，铁磁共振和磁转矩磁强计。样品来自相同的晶圆片。对于名义上完全氧化的样品，我们发现，无论采用何种测量技术，仅仅存在导电界面并不会诱导磁性值超过来自衬底的已经存在的磁性信号。然而，随着氧空位的可控引入，不同的分析技术及其固有的不同灵敏度和与样品中可能的磁矩的潜在相互作用产生了关于磁性存在的不同结果。通过各种测量技术获得的这些意想不到的差异可能是文献中关于LaAlO3/SrTiO3界面存在铁磁性的分歧的来源。
We report on extensive investigations of magnetism at the n-type LaAlO3/SrTiO3 interface performed by utilizing a spectrum of local and integrative analytical techniques: Scanning superconducting quantum interference device microscopy, polar Kerr magnetometry, ferromagnetic resonance, and magnetic torque magnetometry. The samples originated from the same wafers. For nominally fully oxidized samples, we find that the mere presence of the conducting interface does not induce magnetism to values exceeding already present magnetic signals originating from the substrates, irrespective of the measurement technique. With the controlled introduction of oxygen vacancies, however, the different analytical techniques with their inherently different sensitivities and potential interactions with possible magnetic moments in the samples yield different results concerning the existence of magnetism. These unexpected differences obtained with the various measurement techniques are a possible source of the disagreement in the literature about the existence of ferromagnetism at LaAlO3/SrTiO3 interfaces.