We present magnetization and Hall effect measurements on the pyrochlore iridate Nd2Ir2O7. Previous muon spin rotation measurements have shown that the system undergoes an unusual transition at TM = 110 K into a magnetic phase lacking long-range order, followed by a transition at TLRO = 6 K into a state with long-range magnetic order. We observe a small remnant magnetization when cycling through zero magnetic field at temperatures below TM. Below TLRO, this remnant magnetization increases sharply, and new hysteresis effects appear at a higher field Bc = 2.5 T, while the Hall resistance develops a non-monotonic and hysteretic magnetic field dependence, with a maximum at Bc and signatures of an anomalous Hall effect. The dependence on field sweep direction demonstrates a non-trivial transition into a magnetically ordered state with properties paralleling those of known spin-ice systems and suggests a spin reorientation transition across the metal insulator transition in the A-227 series.
@article{arxiv.1212.5565,
title = {Magnetization and Hall effect studies on the pyrochlore iridate Nd2Ir2O7},
author = {S. M. Disseler and S. R. Giblin and Chetan Dhital and K. C. Lukas and Stephen D. Wilson and M. J. Graf},
journal= {arXiv preprint arXiv:1212.5565},
year = {2015}
}