Magnetodielectric coupling in MnCr2O4 spinel

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:321

Article; Proceedings Paper

Mufti, N.¹  Blake, G. R.¹  Palstra, T. T. M.¹ 

[1] Univ Groningen, Zernike Inst Adv Mat, NL-9747 AG Groningen, Netherlands

关键词: Magnetoelectric;    Multiferroic;    Spinel;   

DOI  :  10.1016/j.jmmm.2009.02.023

来源: Elsevier

【 摘 要 】

We have investigated the magnetic and dielectric properties of polycrystalline samples of the spinel MnCr2O4. Below the ferrimagnetic ordering temperature at T-N similar to 43 K, both magnetization and dielectric measurements show signatures of the onset of a conical structure at T-s similar to 17 K and a lock-in temperature at T-f similar to 14 K. These values are similar to those previously reported for single-crystal samples, where the spiral structure is short-range ordered (SRO) at low temperatures. The application of magnetic field suppresses the dielectric anomaly at T-f indicating that the coherence length of the ordering increases. MnCr2O4 exhibits a symmetrical magnetodielectric response between T-f and T-s that scales with the square of the magnetization. This suggests that the magnetodielectric coupling originates from the (PM2)-M-2 term in the free energy expansion. The magnetodielectric response becomes asymmetric with respect to field below T-f. (C) 2009 Elsevier B.V. All rights reserved.

【 授权许可】

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