Structural, magnetic and magnetocaloric properties of hexagonal multiferroic Yb1−xScxMnO3 (x = 0.1 and 0.2)

Abstract

We have studied the effect of Sc doping on the structural, magnetic and magnetocaloric properties of multiferroic Yb_1−xSc_xMnO₃ (x = 0.1 and 0.2). X-ray powder diffraction shows that both samples crystallize in the hexagonal phase with P6₃cm space group. The structural analysis shows a decrease in the lattice parameter a, a decrease in the cell volume of the hexagonal unit cell and a decrease in the average bond length between Mn–O, with Sc substitution. Magnetic measurements show that the Néel temperature (T_N) increases from 90 K for x = 0.1 to 94 K for x = 0.2 samples. Isothermal magnetic curves show that the field variation in magnetization generates a metamagnetic transition. The maximum entropy change −ΔS^max_M and the relative cooling power (RCP) of Yb_1−xSc_xMnO₃ are found to be 2.46 ± 0.40 J mol⁻¹ K⁻¹ and 38.5 ± 9 J mol⁻¹ for x = 0.1 and 1.87 ± 0.31 J mol⁻¹ K⁻¹ and, 30.1 ± 8 J mol⁻¹ for x = 0.2 with ΔH = 10 T. The rescaled magnetic entropy change curves for different applied fields collapse onto a single curve for materials with second-order phase transitions.