Transport properties around the metal-insulator transition for SrVO3 ultrathin films fabricated by electrochemical etching
Transport properties around the metal-insulator transition for SrVO3 ultrathin films fabricated by electrochemical etching
复制标题
电化学刻蚀制备SrVO3超薄膜金属-绝缘体过渡周围的输运性质
DOI：
10.1103/physrevb.105.045138
复制
发表时间：
2021-05
影响因子：
3.7
通讯作者：
H. Okuma;Y. Katayama;K. Otomo;K. Ueno
中科院分区：
文献类型：
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作者：
H. Okuma;Y. Katayama;K. Otomo;K. Ueno
通过使用电化学蚀刻，我们制备了导电超薄的SrVO₃（SVO）薄膜，其在低至3个单分子层（ML）时仍表现出金属特性。从观察到的随着薄膜厚度减小输运性质的系统性变化中发现，在蚀刻过程中薄膜的无序度几乎保持不变，只是厚度减小了。这与沉积态的SVO超薄薄膜所呈现的绝缘行为形成对比。对于蚀刻后的薄膜，在200 K时，当薄膜厚度在10 ML以下减小时，电子迁移率降低，这是由于在金属 - 绝缘体转变附近散射率增加以及电子有效质量增大所致。对于低至3 ML的蚀刻薄膜，通常观察到电阻率在低温下略有上升以及正磁阻现象，这可以通过弱无序金属中电子的弱反局域化来解释。
By using electrochemical etching, we fabricated conductive ultrathin SrVO3 (SVO) films that exhibited metallic behavior down to 3 monolayers (ML). From an observed systematic change in transport properties with decreasing film thickness, it was found that the disorder in the films remained nearly unchanged during etching, and only the thickness was reduced. This is in contrast to the insulating behavior found for as-deposited SVO ultrathin films. For the etched films, the electron mobility at 200 K decreased with decreasing film thickness below 10 ML, originating from an increased scattering rate and electron effective mass near the metal-insulator transition A slight upturn in the resistivity and a positive magnetoresistance at low temperatures were typically observed for the etched films down to 3 ML, which was explained by weak anti-localization of electrons in a weakly disordered metal.