Structural and magnetic properties of DyCrTiO₅ nanoparticles

The compounds with the general chemical formula RCrTiO₅ (R = rare-earth ions) has an orthorhombic crystal structure having Pbam space group. However, there are limited work carried out on this group of materials, primarily in bulk to explore their structural and magnetic properties. The exploration of structural and magnetic properties of RCrTiO₅ compounds in the nano dimension has not been reported to date. This report focuses on the synthesis of DyCrTiO₅ nanoparticles using a simple, time saving and cost-effective sol–gel technique to investigate the role of size on structural as well as magnetic properties. The synthesized sample is calcined at 800 °C for three hours. The crystal structure is confirmed from the Le-Bail profile fitting of the x-ray diffraction (XRD) pattern. The DyCrTiO₅ nanoparticles are crystallized in an orthorhombic structure with lattice parameters, a, b, c of 7.321 ± 0.001, 8.644 ± 0.002 and 5.840 ± 0.001 Å, respectively. The average particle size is found to be 53 ± 3 nm from transmission electron microscopy (TEM). From the temperature-dependent magnetization measurement, the obtained Néel temperature (T_N) is 147 ± 2 K. In contrast to the bulk form, DyCrTiO₅ nanoparticles do not show spin reorientation (SR) which is observed below 37 K or the magnetic compensation because of the dominating contribution of Dy³⁺ moment. In addition, the irreversibility in magnetization is suppressed when measured as a function of temperature in the heating and cooling cycle of the measurement with increasing the probing magnetic field. This indicates a feature similar to kinetic arrest. In isothermal magnetization measurements, exchange bias effect is observed because of interaction between the uncompensated spins on the surface of the nanoparticles.