Emergent Magnetic State in (111)-Oriented Quasi-Two-Dimensional Spinel Oxides

Published

December 11, 2019

Author(s)

Xiaoran Liu, Sobhit Singh, Brian Kirby, Zhicheng Zhong, Yanwei Cao, Banabir Pal, Mikhail Kareev, Srimanta Middey, John W. Freeland, Padraic Shafer, Elke Arenholz, David Vanderbilt, Jak Chakhalian

Abstract

We report on the emergent magnetic state of (111)-oriented CoCr₂O₄ ultrathin films sandwiched by Al₂O₃ in the quantum confined geometry. At the two-dimensional crossover, polarized neutron reflectometry reveals an anomalous enhancement of the total magnetization compared to the bulk value. Synchrotron x-ray magnetic circular dichroism (XMCD) demonstrates the appearance of long-range ferromagnetic ordering of spins on both Co and Cr sublattices. Brillouin function analyses further corroborates that the observed phenomena are due to the strongly altered magnetic frustration, manifested by the onset of a Yafet-Kittel type ordering as the new ground state in the ultrathin limit, which is unattainable in the bulk.

Citation

Nano Letters

Volume

19

Issue

12

Pub Type

Journals

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Keywords

Oxide magnetism, neutron scattering, x-ray scattering

Citation

Liu, X. , Singh, S. , Kirby, B. , Zhong, Z. , Cao, Y. , Pal, B. , Kareev, M. , Middey, S. , Freeland, J. , Shafer, P. , Arenholz, E. , Vanderbilt, D. and Chakhalian, J. (2019), Emergent Magnetic State in (111)-Oriented Quasi-Two-Dimensional Spinel Oxides, Nano Letters, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=928221 (Accessed December 14, 2024)