Anisotropic high-field magnetoresistance of microstructured CeIrIn5

We report magnetoresistance up to 65T on high quality, focused ion beam (FIB)-fabricated microstructures of CeIrIn5, a strongly correlated metal known for its heavy-fermion superconducting state at Tc ~ 0.4K. We probe the anisotropic magnetotransport in microstructured samples with well-defined geometries, and we simultaneously measure resistance along the [100] and [001] directions with respect to a number of applied filed orientations. We observe a jump-like increase of the magnetoresistance in high fields above 40T for a narrow range of field angles. The transport anomaly is reminiscent of recent transport observations in CeRhIn5. Yet, unlike CeRhIn5, CeIrIn5 does not order anti-ferromagnetically; thus, our results point to origins other than metamagnetism.