Simulating spin waves in entropy stabilized oxides
ORAL
Abstract
The entropy stabilized oxide Mg0.2Co0.2Ni0.2Cu0.2Zn0.2O exhibits antiferromagnetic order and magnetic excitations, as revealed by recent neutron scattering experiments. This observation raises the question of the nature of spin wave excitations in such disordered systems. Here, we investigate theoretically the magnetic ground state and the spin-wave excitations using linear spin-wave theory in combination with the supercell approximation to take into account the extreme disorder in this magnetic system. We find that the experimentally observed antiferromagnetic structure can be stabilized by a rhombohedral distortion together with large second nearest neighbor interactions. Our calculations show that the spin-wave spectrum consists of a well-defined low-energy coherent spectrum in the background of an incoherent continuum that extends to higher energies.
*TB, DP, RH and RF were supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. We used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. DOE under Contract No. DE-AC02-05CH11231. GA was supported by the scientific Discovery through Advanced Computing (SciDAC) program funded by U.S. Department of Energy, Office of Science, Advanced Scientific Computing Research and Basic Energy Sciences, Division of Materials Sciences and Engineering. Part of this research was conducted at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility.
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Publication:Tom Berlijn, Gonzalo Alvarez, David S. Parker, Raphaël P. Hermann, and Randy S. Fishman, Phys. Rev. Research 3, 033273 (2021).
