Measurement of the internal magnetic field in the correlated iridates Ca4IrO6, Ca5Ir3O12, Sr3Ir2O7 and Sr2IrO4

Journal article

Oxides containing iridium ions display a range of magnetic and conducting properties that depend on the delicate balance between interactions and are controlled, at least in part, by the details of the crystal architecture. We have used muon spin rotation (μSR) to study the local field in four iridium oxides, Ca 4IrO 6, Ca 5Ir 3O 12, Sr 3Ir 2O 7, and Sr 2IrO 4, which show contrasting behavior. Our μSR data on Ca 4IrO 6 and Ca 5Ir 3O 12 are consistent with conventional antiferromagnetism where quasistatic magnetic order develops below T N=13.85(6) and 7.84(7) K, respectively. A lower internal field is observed for Ca 5Ir 3O 12, as compared to Ca 4IrO 6, reflecting the presence of both Ir4 + and Ir5 + ions and resulting in a more magnetically dilute structure. Muon precession is only observed over a restricted range of temperature in Sr 3Ir 2O 7, while the Mott insulator Sr 2IrO 4 displays more complex behavior, with the μSR signal containing a single, well-resolved precession signal below T N=230 K, which splits into two precession signals at low temperature following a reorientation of the spins in the ordered state. © 2011 American Physical Society.

Authors: Franke, I; Baker, P; Blundell, S; Lancaster, T; Hayes, W

• Publication status: Published
• Journal: Physical Review B
• Volume: 83
• Issue: 9
• Publication date: 2011-03-15
• DOI: 10.1103/PhysRevB.83.094416
• EISSN: 1550-235X
• ISSN: 1098-0121
• Language: English