Configurable Crack Wall Conduction in a Complex Oxide

• DOI: 10.1021/acs.nanolett.2c02640
• Publication Date: 2023-01-03T17:46:06Z
• Authors: Youngki Yeo; Soo-Yoon Hwang; Jinwook Yeo; Jihun Kim; Jinhyuk Jang; Heung-Sik Park; Yong-Jin Kim; Duc Duy Le; Kyung Song; Moonhong Kim; Seunghwa Ryu; Si-Young Choi; Chan-Ho Yang
• Keywords: 0301 basic medicine; 03 medical and health sciences; 669

Mobile defects in solid-state materials play a significant role in memristive switching and energy-efficient neuromorphic computation. Techniques for confining and manipulating point defects may have great promise for low-dimensional memories. Here, we report the spontaneous gathering of oxygen vacancies at strain-relaxed crack walls in SrTiO3 thin films grown on DyScO3 substrates as a result of flexoelectricity. We found that electronic conductance at the crack walls was enhanced compared to the crack-free region, by a factor of 104. A switchable asymmetric diode-like feature was also observed, and the mechanism is discussed, based on the electrical migration of oxygen vacancy donors in the background of Sr-deficient acceptors forming n+-n or n-n+ junctions. By tracing the temporal relaxations of surface potential and lattice expansion of a formed region, we determine the diffusivity of mobile defects in crack walls to be 1.4 × 10-16 cm2/s, which is consistent with oxygen vacancy kinetics.