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arXiv · 1810.07871

Probing the role of Nd3+ ions in the weak multiferroic character of NdMn2O5 by optical spectroscopies

S. Mansouri·S. Jandl·M. Balli·P. Fournier·B. Roberge·M. Orlita·I. A. Zobkalo·S. N. Barilo·S. V. Shiryaev
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Abstract

Raman and infrared spectroscopies are used as local probes to study the dynamics of the Nd-O bonds in the weakly multiferroic NdMn2O5 system. The temperature dependence of selected Raman excitations reveals the splitting of the Nd-O bonds in NdMn2O5. The Nd3+ ion crystal field (CF) excitations in NdMn2O5 single crystals are studied by infrared transmission as a function of temperature, in the 1800-8000 cm-1 range, and under an applied magnetic field up to 11 T. The frequencies of all 4Ij crystal-field levels of Nd3+ are determined. We find that the degeneracy of the ground-state Kramers doublet is lifted ({\Delta}0 ~7.5 cm-1) due to the Nd3+-Mn3+ interaction in the ferroelectric phase, below TC ~ 28 K. The Nd3+ magnetic moment mNd(T) and its contribution to the magnetic susceptibility and the specific heat are evaluated from {\Delta}0(T) indicating that the Nd3+ ions are involved in the magnetic and the ferroelectric ordering observed below ~ 28 K. The Zeeman splitting of the excited crystal field levels of the Nd3+ ions at low temperature is also analyzed.

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S. Mansouri, S. Jandl, M. Balli, P. Fournier, B. Roberge, M. Orlita, I. A. Zobkalo, S. N. Barilo, S. V. Shiryaev. 2018-10-18. Probing the role of Nd3+ ions in the weak multiferroic character of NdMn2O5 by optical spectroscopies. https://doi.org/10.1103/physrevb.98.205119

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