Implications of magnetic and magnetodielectric behavior of GdCrTiO5

TL;DR

This study investigates the magnetic, dielectric, and magnetodielectric properties of GdCrTiO5, revealing suppressed Cr magnetic ordering, field-dependent dielectric anomalies, and potential short-range magnetic order effects, contributing to understanding multiferroic behavior.

Contribution

It provides new insights into the magnetic and dielectric behavior of GdCrTiO5, highlighting the role of Gd 4f orbitals and magnetodielectric coupling, with comparisons to related multiferroics.

Findings

Suppressed Cr magnetic ordering temperature compared to NdCrTiO5

Magnetodielectric coupling evidenced by field-dependent dielectric peaks

Raman spectra indicate magnetic origin of spectral weight changes

Abstract

We have carried out dc magnetization (M), heat-capacity (C) and dielectric studies down to 2K for the compound GdCrTiO5, crystallizing in orthorhombic Pbam structure, in which well-known multiferroics RMn2O5 (R= Rare-earths) form. The points of emphasis are: (i) The magnetic ordering temperature of Cr appears to be suppressed compared to that in isostructural Nd counterpart, NdCrTiO5, for which the Neel temperature is about 21 K. This finding on the Gd compound suggests that Nd 4f orbital plays a role on the magnetism of Cr in contrast to a proposal long ago. (ii) Dielectric constant does not exhibit any notable feature below about 30 K in the absence of external magnetic field, but a peak appears and gets stronger with the application of external magnetic fields, supporting the existence of magnetodielectric coupling. (iii) The dielectric anomalies appear even near 100 K, which can be attributed to short-range magnetic-order. We also observe a gain in spectral weight below about 150 K in Raman spectra in the frequency range 150 to 400 cm-1, which could be magnetic in origin supporting short-range magnetic order. It is of interest to explore whether geometrically frustration plays any role on the dielectric properties of this family, as in the case of RMn2O5.