We report the effect of oxygen pressure during growth (PO2) on the electronic and magnetic properties of PrAlO3 films grown on TiO2-terminated SrTiO3 substrates. Resistivity measurements show an increase in the sheet resistance as PO2 is increased. The temperature dependence of the sheet resistance at low temperatures is consistent with Kondo theory for PO2≥10−5 torr. Hall effect data exhibit a complex temperature dependence that suggests a compensated carrier density. We observe behavior consistent with two different types of carriers at interfaces grown at PO2≥10−4 torr. For these interfaces, we measured a moderate positive magnetoresistance (MR) due to a strong spin-orbit (SO) interaction at low magnetic fields that evolves into a larger negative MR at high fields. Positive high MR values are associated with samples where a fraction of carriers are derived from oxygen vacancies. Analysis of the MR data permitted the extraction of the SO interaction critical field ( e.g. HSO=1.25 T for PO2=10−5 torr). The weak anti-localization effect due to a strong SO interaction becomes smaller for higher PO2 grown samples, where MR values are dominated by the Kondo effect, particularly at high magnetic fields.
@article{arxiv.1606.02308,
title = {Spin-Orbit Interaction and Kondo Scattering at the PrAlO$_3$/SrTiO$_3$ Interface: Effects of Oxygen Content},
author = {Shirin Mozaffari and Samaresh Guchhait and John T. Markert},
journal= {arXiv preprint arXiv:1606.02308},
year = {2017}
}