Tuning the J_eff = 1/2 Insulating State Via Electron Doping and Pressure in the Double-Layered Iridate Sr₃Ir₂O₇

Authors

L. Li, University of Kentucky
P. P. Kong, Chinese Academy of Sciences, China
Tongfei Qi, University of KentuckyFollow
C. Q. Jin, Chinese Academy of Sciences, China
Shujuan Yuan, University of KentuckyFollow
Lance E. DeLong, University of KentuckyFollow
P. Schlottmann, Florida State University
Gang Cao, University of KentuckyFollow

Abstract

Sr₃Ir₂O₇ exhibits a novel J_eff = 1/2 insulating state that features a splitting between J_eff = 1/2 and 3/2 bands due to spin-orbit interaction. We report a metal-insulator transition in Sr3Ir2O7 via either dilute electron doping (La³⁺ for Sr²⁺) or application of high pressure up to 35 GPa. Our study of single-crystal Sr₃Ir₂O₇ and (Sr_1−xLa_x)₃Ir₂O₇ reveals that application of high hydrostatic pressure P leads to a drastic reduction in the electrical resistivity by as much as six orders of magnitude at a critical pressure P_C = 13.2 GPa, manifesting a closing of the gap; but further increasing P up to 35 GPa produces no fully metallic state at low temperatures, possibly as a consequence of localization due to a narrow distribution of bonding angles θ. In contrast, slight doping of La³⁺ ions for Sr²⁺ ions in Sr₃Ir₂O₇ readily induces a robust metallic state in the resistivity at low temperatures; the magnetic ordering temperature is significantly suppressed but remains finite for (Sr_0.95La_0.05)₃Ir₂O₇ where the metallic state occurs. The results are discussed along with comparisons drawn with Sr₂IrO₄, a prototype of the J_eff = 1/2 insulator.

Document Type

Article

Publication Date

6-21-2013

Notes/Citation Information

Published in Physical Review B, v. 87, issue 23, 235127, p. 1-6.

©2013 American Physical Society

The copyright holder has granted permission for posting the article here.

Digital Object Identifier (DOI)

https://doi.org/10.1103/PhysRevB.87.235127

Funding Information

This work was support by the US National Science Foundation under Grant Nos. DMR-0856234 and EPS-0814194, and the US Department of Energy Office of Science, Basic Energy Sciences Grant No. DE-FG02-97ER45653. P.S. is supported by the US Dept. of Energy under Grant No. DE-FG02-98ER45707.

Repository Citation

Li, L.; Kong, P. P.; Qi, Tongfei; Jin, C. Q.; Yuan, Shujuan; DeLong, Lance E.; Schlottmann, P.; and Cao, Gang, "Tuning the J_eff = 1/2 Insulating State Via Electron Doping and Pressure in the Double-Layered Iridate Sr₃Ir₂O₇" (2013). Physics and Astronomy Faculty Publications. 448.
https://uknowledge.uky.edu/physastron_facpub/448