Enhanced electrical conductivity and diluted Ir4+ spin orders in electron doped iridates Sr2 –xGaxIrO4

Sr2IrO4 represents a fascinating system to study comparable electronic correlations and spin-orbit couplings, and recently attracts considerable attention in high-temperature superconductivity. Here, we report on the transport and magnetic properties in gallium-doped Sr2IrO4. A metallic state is discovered whendopingx is over 0.1, which could be understood in terms of the quickly decreasedenergy gap and increasedcarrier concentration. In addition to the high-temperature magnetictransition (TC > 200 K), a low-temperature one (TC′) is also observed for thex = 0.05–0.10 samples. Both of the magnetic states are found to be cantedantiferromagnetism. The low-temperature phase is strongly depressed bydoping and vanishes whendoping is further increased, which is probably stabilized by the long-wayexchange interactions of diluted Ir4+ spins via Ir3+ ions. Our studies provide an insight into the electrical and magnetic states tuned by chemicaldoping in Sr2IrO4, thereby facilitating the seeking of superconductivity in this system.

Source: Applied Physics Letters - November 9, 2016 Category: Physics Authors: Tao Han, Yongjian Wang, Jun Yang, Lei He, Junmin Xu, Dandan Liang, Hui Han, M. Ge, C. Y. Xi, W. K. Zhu, Changjin Zhang and Yuheng Zhang Source Type: research