Affiliation:
1. Shenzhen Key Laboratory of Special Functional Materials Guangdong Provincial Key Laboratory of New Energy Materials Service Safety College of Materials Science and Engineering Shenzhen University Shenzhen 518060 China
2. College of Electronic Information and Mechatronic Engineering Zhaoqing University Duanzhou District Zhaoqing 526061 China
3. Quantum Science Center of Guangdong‐Hong Kong‐Macao Greater Bay Area Shenzhen 518045 China
4. Department of Applied Physics The Hong Kong Polytechnic University Hung Hom Hong Kong 999077 China
Abstract
AbstractThe chemical and electronic interactions at metal/oxide heterojunctions is pivotal in determining the electronic properties of oxide devices utilized in microelectronics, catalysis, and photovoltaic systems. In this study, interfacial oxidation migrations within a model heterostructure system, consisting of a La0.7Sr0.3MnO3 film overlaid by various metallic (Ti, Al, Cu, Ag, and Au) ultrathin layers are systematically investigated. It is experimentally demonstrated that at elevated deposition temperature, the oxygen‐active ultrathin overlayers of base metals such as Ti and Al significantly derive oxygen from the underlying La0.7Sr0.3MnO3 film, inducing a perovskite to brownmillerite phase transition in the underlying functional oxide film. Conversely, no structural transitions are observed for La0.7Sr0.3MnO3 film when it is capped by noble metals (Au, Ag), which possess relative high oxidation formation energy. These observations are crucial for the development of novel crystalline and electronic architectures in metal/oxide heterostructures, offering a refined approach to modulate interfacial reactivity without compromising the functionality of oxide‐based heterojunction devices.
Funder
National Natural Science Foundation of China