Probing Dy3+ magnetic moments in multiferroic perovskite DyMnO3 by optical spectroscopy

TL;DR

This study uses optical spectroscopy to analyze the magnetic moments of Dy3+ ions in DyMnO3, revealing detailed crystal-field levels, temperature-dependent magnetic splitting, and the Dy-Mn interaction type.

Contribution

It provides a comprehensive spectroscopic characterization of Dy3+ in DyMnO3 and identifies the Dzyaloshinskii-Moriya interaction as the key magnetic coupling mechanism.

Findings

Determined energies of 36 crystal-field levels of Dy3+

Observed temperature-dependent splitting of Dy3+ ground doublet

Concluded Dy-Mn interaction is of Dzyaloshinskii-Moriya type

Abstract

We present a detailed temperature-dependent spectroscopic study of DyMnO3 single crystals with distorted perovskite structure. Energies of 36 crystal-field levels of Dy3+ in paramagnetic DyMnO3 were determined. The Dy3+ ground Kramers doublet does not split at T_N^Mn = 39 K and splits below Tlock = 18 K. The splitting grows fast at temperatures near T_N^Dy = 6.5 K and reaches {\Delta}0 = 11 cm-1 at 4 K. Using the experimental temperature dependence {\Delta}0(T), we calculate the dysprosium magnetic moment mDy(T) and the dysprosium contribution into specific heat and magnetic susceptibility. Analysing all the experimental data, we conclude that the Dy-Mn interaction is of the Dzyaloshinskii-Moriya type.