Temperature evolution of the effective magnetic anisotropy in the MnCr${}_2$O${}_4$ spinel

Abstract

In this work we present a study of the low temperature magnetic phases of polycrystalline MnCr${}_2$O${}_4$ spinel through dc magnetization and ferromagnetic resonance spectroscopy (FMR). Through these experiments we determined the main characteristic temperatures: T${}_C$ $\sim$41 K and T${}_H$ $\sim$18 K corresponding, respectively, to the ferrimagnetic order and to the low temperature helicoidal transitions. The temperature evolution of the system is described by a phenomenological approach that considers the different terms that contribute to the free energy density. Below the Curie temperature the FMR spectra were modeled by a cubic magnetocrystalline anisotropy to the second order, with $K_1$ and $K_2$ anisotropy constants that define the easy magnetization axis along the <110> direction. At lower temperatures, the formation of a helicoidal phase was considered by including uniaxial anisotropy axis along the [1-10] propagation direction of the spiral arrange, with a $K_u$ anisotropy constant. The values obtained from the fittings at 5 K are $K_1$=-2.3x10${}^4$ erg/cm${}^3$, $K^2$=6.4x10${}^4$ erg/cm${}^3$ and $K_u$=7.5x10${}^4$ erg/cm${}^3$.

21 pages, 6 figures

References in corpus (2)

• Multiferroics: different ways to combine magnetism and ferroelectricity
• Enhanced Pressure Dependence of Magnetic Exchange in A2+[V2]O4 Spinels Approaching the Itinerant Electron Limit

Cited by in corpus (2)

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