Structure driven magnetic properties and magnetodielectric coupling in a mixed metal oxide NdCr_0.5Co_0.5O₃

Abstract

Mixed-metal oxides provide a vast playground to enhance and tune the functional properties, as compared to the respective parent oxides. In this context, we report the magnetic, thermal, dielectric, and magnetodielectric properties of NdCr0.5Co0.5O3. Three magnetic transitions, TN1 – antiferromagnetic ordering of Cr3+ cations from paramagnetic state, TN2 – spin reorientation of these Cr3+ cations, and TN3 – due to Nd ordering induced by the Cr sub-lattice; have been observed, due to a reduction in orthorhombic distortion. Modification of magnetic interactions is also noted because of the presence of Co cations in NdCrO3 matrix. The reduction in Nd3+-Cr3+ interactions is further concluded from the Schottky anomaly in the heat capacity, which arises due to Zeeman splitting of the ground state Kramer’s doublet of Nd3+ cations. The presence of significant magnetodielectric coupling (~ 4%) below TN2 has been observed. Additionally, double relaxor-like behaviour around 176 and 230 K, with activation energy ~ 0.24 and 0.32 eV, is observed due to charge carrier hopping at Cr/Co-site. Our studies indicate that structure-driven modifications of Cr3+- Cr3+ and Nd3+-Cr3+ interactions are responsible for enhanced value magnetic transitions and magnetodielectric coupling in NdCr0.5Co0.5O3, as compared to its respective parent compounds.