Predicted New Transition Metal Oxides for Photovoltaics and Spintronics
Guang-Yu Guo1*
1Department of Physics, National Taiwan University, Taipei City, Taiwan
* Presenter:Guang-Yu Guo,
Transition metal oxides have attracted intense interest in the societies of chemistry, physics and material science. In particular, they play a crucial role in energy storage and conversion, e.g., Li battery, solar cell, and solid fuel cell. In this talk, I will first report novel double perovskites ScFe1-xCrxO3 (1/6 I will then present a systematic first-principles study of the magnetic and electronic properties of the (111) superlattices (ABO3)2/(AB'O3)10 of 4d and 5d transition metal perovskite (B = Ru, Rh, Ag, Re, Os, Ir, Au; AB'O3 = LaAlO3, SrTiO3) [2]. We demonstrate that bilayers (LaBO3)2 (B = Ru, Re, Os) and (SrBO3)2 (B = Rh, Os, Ir) are ferromagnetic with ordering temperatures up to room temperature. In particular, bilayer (LaOsO3)2 is an exotic spin-polarized quantum anomalous Hall insulator, while the other ferromagnetic bilayers are metallic with large Hall conductances comparable to the conductance quantum. Furthermore, bilayers (LaRuO3)2 and (SrRhO3)2 are half-metallic, while bilayer (SrIrO3)2 exhibits peculiar colossal magnetic anisotropy. Our findings thus show that 4d and 5d metal perovskite (111) bilayers are a class of quasi-two-dimensional materials for exploring exotic quantum phases and also for advanced applications such as low-power nanoelectronics and oxide spintronics. [2].
The speaker thanks Hirak Kumar Chandra, Cheng-Yu Liu, Tien-Yi Cai and Sheng Ju for collaborations.
[1] T.-Y. Cai, S.-C. Liu, S. Ju, C.-Y. Liu and G. Y. Guo, “Multiferroic double perovskites ScFe1-xCrxO3 (1/6[2] H. K. Chandra and G. Y. Guo, “Quantum anomalous Hall phase and half-metallic phase in ferromagnetic (111) bilayer of 4d and 5d transition metal perovskites,” arXiv:1512.08843; Phys. Rev. B 95, 134448 (2017).

Keywords: perovskite oxide, magnetism, photovoltaic, Chern insulator, quantum anomalous Hall effect