Structural properties of slightly off-stoichiometric homoepitaxial SrTixO3-δ thin films
Structural properties of slightly off-stoichiometric homoepitaxial SrTixO3-δ thin films
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DOI：
10.1063/1.1305827
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发表时间：
2000-08-15
影响因子：
3.2
通讯作者：
Obst, B
中科院分区：
文献类型：
--
作者：
Fuchs, D;Adam, M;Obst, B
采用射频磁控溅射法在取向的SrTiO_3单晶衬底上生长了缺Ti的SrTiO_xO_3-δ薄膜（x < 1）< 100 >。通过溅射气体压力调节Ti缺陷。在扫描电子显微镜中通过卢瑟福背散射和能量色散X射线分析确定Ti/Sr阳离子比x。为了获得关于Ti/O比的信息，还进行了X射线吸收光谱。我们研究了SrTixO 3-delta薄膜，x=0.98，0.95和0.89。外延生长和晶格缺陷，其特征在于通过X射线衍射，电子衍射和高分辨率透射电子显微镜。薄膜结晶为四方晶系结构，最大镶嵌展度约为0.1度。c轴垂直于衬底表面取向，其中c晶格参数随着x的减小而增加。对于x > 0.89，Ti不足主要通过改变阳离子亚晶格上的位置占据并结合氧空位来补偿，即，当x < 0.95时，观察到Ruddlesden-Popper相Srn+1 TinO_（3 n +1）系列的同源物的共生。的薄膜的介电性能进行了简要的讨论（SrTiVO）的缺陷复合物。(C)2000年美国物理学会。【S0021-8979（00）02016-8】。
Ti-deficient SrTixO3-delta films, x < 1, were grown on < 100 > oriented SrTiO3 single crystal substrates by radio frequency magnetron sputtering from stoichiometric targets. The Ti-deficiency was adjusted by the sputtering gas pressure. The Ti/Sr cation ratio, x, was determined by Rutherford backscattering and energy dispersive x-ray analysis in a scanning electron microscope. To obtain information on the Ti/O ratio, x-ray absorption spectroscopy was carried out as well. We investigated SrTixO3-delta films with x=0.98, 0.95, and 0.89. The epitaxial growth and lattice imperfections were characterized by x-ray diffraction, electron diffraction, and high resolution transmission electron microscopy. The films crystallized in a tetragonal structure with a maximum mosaic spread of about 0.1 degrees. The c axis was oriented perpendicular to the substrate surface where the c-lattice parameter was increasing with decreasing x. For x > 0.89, the Ti deficiency was primarily compensated by a change of the site occupation on the cation sublattices in combination with oxygen vacancies, i.e., the formation of Sr-Ti and V-O point defects, whereas for x < 0.95 the intergrowth of homologs series of the Ruddlesden-Popper phases, Srn+1TinO3n+1, was observed. The dielectric properties of the films are briefly discussed in terms of (SrTiVO) defect complexes. (C) 2000 American Institute of Physics. [S0021-8979(00)02016-8].