Studying the effects of interfacial coupling in La0.5Sr0.5CoO3-δ thin films on SrTiO3 using in-situ cooling experiments

Xue Rui, Jeff Walter, Chris Leighton, Robert Klie
2017 Microscopy and Microanalysis  
Hole-doped LaxSr1-xCoO3-δ has been attracted much attention due to its rich magnetic behavior and intriguing electronic transport properties [1]. At x=0.5, the heavily doped cobalt oxide not only exhibits a change in valence from Co 3+ to Co 4+ , which induces short-range ferromagnetic ordering, but also results in the formation of oxygen vacancies. In epitaxial thin films, the lattice mismatch between the substrate, such as LaAlO3 (LAO) or SrTiO3 (STO), the LaxSr1-xCoO3-δ film can stabilize
more » ... gen vacancy ordering, which will have significant effects on the films' magnetism and electronic transport properties [2] . In addition, for films grown on STO, the anti-ferrodistortive phase transition at 105 K can further affect the structure and transport properties of the thin films. For example, La0.5Sr0.5CoO3-δ (LSCO) films grown on STO substrates have exhibited coupling between the out-of-phase TiO6 octahedral rotation in STO at around 105 K and the interfacial CoO6 octahedral network [3] . Furthermore, smaller Jahn-Teller distortions in CoO6 make it possible for these coupling effects to propagate as far as 10 nm into the LSCO thin film and influence the magnetic/transport properties [4] . However, a detailed understanding of the local atomic and electronic structures, as well as the interplay between oxygen vacancy ordering and the low-temperature phase transitions at the atomic scale remains elusive. 850
doi:10.1017/s1431927617004913 fatcat:bw4yoiww6zhupnnoifpjhtlgvy