• DOI:10.1103/PhysRevB.98.024415
• Corpus ID: 53069846

Disentangling orbital and spin exchange interactions for Co2+ on a rocksalt lattice

@article{Sarte2018DisentanglingOA,
  title={Disentangling orbital and spin exchange interactions for 
Co2+
 on a rocksalt lattice},
  author={P M Sarte and Roger Arthur Cowley and Efrain E. Rodriguez and E. Pachoud and Duc-Anh Le and V Garc{\'i}a-Sakai and J. W. Taylor and Christopher D. Frost and Dharmalingam Prabhakaran and Chris MacEwen and Atsushi Kitada and Alexander J. Browne and M Songvilay and Zahra Yamani and William J. L. Buyers and John Paul Attfield and Christopher Stock},
  journal={Physical Review B},
  year={2018}
}

• P. M. Sarte, R. Cowley, +14 authors C. Stock
• Published 13 July 2018
• Physics
• Physical Review B

Neutron spectroscopy was applied to study the magnetic interactions of orbitally degenerate Co2+ on a host MgO rocksalt lattice where no long-range spin or orbital order exists. The paramagnetic nature of the substituted monoxide Co0.03Mg0.97O allows for the disentanglement of spin exchange and spin-orbit interactions. By considering the prevalent excitations from Co2+ spin pairs, we extract seven exchange constants out to the fourth coordination shell. An antiferromagnetic next-nearest-neighbor 180◦ exchange interaction is dominant; however, dual ferromagnetic and antiferromagnetic interactions are observed for pairings with other pathways. These interactions can be understood in terms of a combination of orbital degeneracy in the t2g channel and the Goodenough-Kanamori-Anderson rules. Our work suggest that such a hierarchy of exchange interactions exists in transition-metal-based oxides with a t2g orbital degeneracy.