We have measured extremely large coercive magnetic fields of up to 55~T in Sr3NiIrO6, with a switched magnetic moment ≈0.8μB per formula unit. As far as we are aware, this is the largest coercive field observed thus far. This extraordinarily hard magnetism has a completely different origin from that found in conventional ferromagnets. Instead, it is due to the evolution of a frustrated antiferromagnetic state in the presence of strong magnetocrystalline anisotropy due to the overlap of spatially-extended Ir4+ 5d orbitals with oxygen 2p and Ni2+ 3d orbitals. This work highlights the unusual physics that can result from combining the extended 5d orbitals in Ir4+ with the frustrated behaviour of triangular lattice antiferromagnets.
@article{arxiv.1408.0758,
title = {55~Tesla coercive magnetic field in frustrated Sr$_3$NiIrO$_6$},
author = {John Singleton and Jae Wook Kim and Craig V. Topping and Anders Hansen and Eun-Deok Mun and Saman Ghannadzadeh and Paul Goddard and Xuan Luo and Yoon Seok Oh and Sang-Wook Cheong and Vivien S. Zapf},
journal= {arXiv preprint arXiv:1408.0758},
year = {2014}
}