Magnetic phase transitions and magnetocaloric effect in DyCrTiO5 nanoparticles

Abstract

This work focuses on the transitions found in magnetic measurements of DyCrTiO5 nanoparticles with the associated magnetocaloric behavior. The nanoparticles have been synthesized through a fast and easy synthesis technique i.e., sol-gel method and then calcined at 800 °C. The orthorhombic structure of the material with lattice constants, a, b, and c are of 7.3158(7), 8.6431(9), 5.8390(8) Å, respectively, was established from the x-ray diffraction pattern. The transmission electron microscopy result confirms the 37 ± 1 nm particle size of the synthesised sample. The Néel temperature, TN = 153 ± 1 K, was obtained from the magnetic measurement in which magnetization (M) was measured with increasing the temperature (T). In addition, spin reorientation is observed at a temperature TSR = 49 ± 1 K. Irreversibility is seen in the field-cool-cooling curves and field-cool-warming curves of M(T) measurements at low temperatures, not previously observed in bulk samples of this material. The ferromagnetic nature, with the exchange bias effect, is confirmed for the sample from the magnetization measurements at constant temperature by varying the applied field. Additionally, a change in magnetic entropy (−ΔSm) of 10.9 ± 0.1 J kg−1 K−1 is found at a 3 T difference in the field. The obtained magnetic behavior of DyCrTiO5 nanoparticles is discussed in terms of the competing interactions of Cr3+ and Dy3+, respectively.