Iglesias Lucia, Gómez Andrés, Gich Martí, Rivadulla Francisco
Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS), Departamento de Química-Física , Universidade de Santiago de Compostela , 15782 Santiago de Compostela , Spain.
Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) , Campus UAB , Bellaterra , Catalonia 08193 , Spain.
ACS Appl Mater Interfaces. 2018 Oct 17;10(41):35367-35373. doi: 10.1021/acsami.8b12019. Epub 2018 Oct 3.
Understanding diffusion of oxygen vacancies in oxides under different external stimuli is crucial for the design of ion-based electronic devices, improvement of catalytic performance, and so forth. In this manuscript, using an external electric field produced by an atomic force microscopy tip, we obtain the room-temperature diffusion coefficient of oxygen-vacancies in thin films of SrTiO under compressive/tensile epitaxial strain. Tensile strain produces a substantial increase of the diffusion coefficient, facilitating the mobility of vacancies through the film. Additionally, the effect of tip bias, pulse time, and temperature on the local concentration of vacancies is investigated. These are important parameters of control in the production and stabilization of nonvolatile states in ion-based devices. Our findings show the key role played by strain for the control of oxygen vacancy migration in thin-film oxides.
了解不同外部刺激下氧化物中氧空位的扩散对于基于离子的电子器件设计、催化性能提升等至关重要。在本论文中，我们利用原子力显微镜针尖产生的外部电场，获得了在压缩/拉伸外延应变下 SrTiO 薄膜中氧空位的室温扩散系数。拉伸应变使扩散系数大幅增加，促进了空位在薄膜中的迁移。此外，还研究了针尖偏压、脉冲时间和温度对空位局部浓度的影响。这些是基于离子的器件中非易失态产生和稳定控制的重要参数。我们的研究结果表明应变在控制薄膜氧化物中氧空位迁移方面发挥的关键作用。
