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DOE OSTI · 1849754

Metastable antiphase boundary ordering in CaFe 2 O 4

Lane, H.·Rodriguez, E. E.·Walker, H. C.·Niedermayer, Ch.·Stuhr, U.·Bewley, R. I.·Voneshen, D. J.·Green, M. A.·Rodriguez-Rivera, J. A.·Fouquet, P.·Cheong, S.-W.·Attfield, J. P.·Ewings, R. A.·Stock, C.
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Abstract

CaFe 2 O 4 is an $\textit{S}$ = 5/2 antiferromagnet exhibiting two magnetic orders that shows regions of coexistence at some temperatures. Using a Green’s function formalism, we model neutron scattering data of the spin wave excitations in this material, elucidating the microscopic spin Hamiltonian. In doing so, we suggest that the low-temperature A phase order (↑↑↓↓) finds its origins in the freezing of antiphase boundaries created by thermal fluctuations in a parent B phase order (↑↓↑↓). In this work, the low-temperature magnetic order observed in CaFe 2 O 4 is thus the result of a competition between the exchange coupling along $\textit{c}$, which favors the B phase, and the single-ion anisotropy, which stabilizes thermally generated antiphase boundaries, leading to static metastable A phase order at low temperatures.

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Lane, H., Rodriguez, E. E., Walker, H. C., Niedermayer, Ch., Stuhr, U., Bewley, R. I., Voneshen, D. J., Green, M. A., Rodriguez-Rivera, J. A., Fouquet, P., Cheong, S.-W., Attfield, J. P., Ewings, R. A., Stock, C.. 2021-09-02. Metastable antiphase boundary ordering in CaFe 2 O 4. https://doi.org/10.1103/physrevb.104.104404

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