Effects of V and Gd doping on novel positive colossal electroresistance and quantum transport in PbPdO thin films with (002) preferred orientation.

In this work, PbPdVO and PbPdGdO thin films with (002) preferred orientation were prepared using a pulsed laser deposition technique. The temperature dependence of resistivities () was investigated under various applied DC currents. Colossal electroresistance (CER) effects were found in PbPdVO and PbPdGdO. It was found that the positive CER values of PbPdVO and PbPdGdO reach 3816% and 154% for = 1.00 μA at 10 K, respectively. In addition, the () cycle curves of PbPdVO and PbPdGdO thin films showed a critical temperature similar to that of PbPdO ( = 260 K). Particularly, charge transfer between O and O was confirmed by XPS. Additionally, based on first-principles calculations and internal electric field models, the CER and magnetic sources in PbPdVO and PbPdGdO can be well explained. Finally, it was found that thin film samples doped with V and G ions exhibit weak localization (WL) and weak anti-localization (WAL) quantum transport properties. Ion doping leads to a transition from WAL to WL. The study results indicate that PbPdO, one of the few oxide topological insulators, can exhibit novel quantum transport behavior after ion doping.