Lattice defects present in PLD-grown, epitaxial SrRuO_3 thin films on (001) SrTiO_3 substrates are analyzed by high resolution transmission electron microscopy (HRTEM). Before the preparation of TEM samples, the electrical resistivity of films grown at different substrate temperatures was determined. Films grown at 775 deg C exhibited a low electrical resistivity of only 200 um OMEGA cm. They were found to be of orthorhombic structure and containd only few lattice defects. Films grown at 700 deg Cshowed a high electrical resistivikty of 1400 um OMEGA cm. They were of cubic lattice symmetry, while films grown at temperatures above 800 deg C showed resistivities between 300 and 900 um OMEGA cm. The latter films mainly consist of an orthorhombic-cubic phase mix and involve lattice defects of high density, such as twins and antiphase boundaries (APBs). These defects are mainly located in between the islands and obviously contribute to the high film resistivity observed. For example, the APBs contain an extra single SrO layer, which is certainly insulating. Moreover, Ru vacancies are present in these films.
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机译：通过高分辨率透射电子显微镜（HRTEM）分析了在（001）SrTiO_3衬底上PLD生长的外延SrRuO_3薄膜中存在的晶格缺陷。在制备TEM样品之前，要确定在不同基板温度下生长的薄膜的电阻率。在775摄氏度下生长的薄膜显示出仅200 um OMEGA cm的低电阻率。发现它们具有正交结构，并且仅包含少量晶格缺陷。在700摄氏度下生长的薄膜显示出1400 um OMEGA cm的高电阻率。它们具有立方晶格对称性，而在高于800摄氏度的温度下生长的薄膜则显示出300至900 um OMEGA cm之间的电阻率。后者的薄膜主要由正交晶-立方相混合物组成，并涉及高密度的晶格缺陷，例如孪晶和反相边界（APB）。这些缺陷主要位于岛之间，显然有助于观察到的高薄膜电阻率。例如，APB包含一个额外的单一SrO层，该层当然是绝缘的。此外，这些膜中存在Ru空位。
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