Influence of particle size on the magnetocaloric and dielectric properties of GdCrO3

In this paper, the GdCrO3 polycrystalline samples with different particle sizes were prepared by the sol–gel method and the structure, vacancy defects, magnetocaloric property, dielectric property were investigated in detail. The results indicate that the lattice constant and vacancy defects can be affected greatly by the particle size. With the particle sizes increases, the magnetic entropy becomes larger at first, and then it decreases accompanying particle size becomes larger than 395 nm. That is, the d = 395 nm sample presents the best magnetocaloric property and the maximum magnetic entropy (− ΔSM) and the refrigerant capacity (RCP) at T = 3 K and H = 3 T condition is 33.41 J·kg−1 K−1 and 552.4 J kg−1. The temperature and magnetic field dependent permittivity also confirm the magneto-dielectric effect of the prepared GdCrO3. As the particle size increases, the coupling coefficient enhanced continuously. Especially for the d = 485 nm sample, a small field of 1 T could cause the dielectric constant increases by about 10%. This work suggests that increasing the particle size is an effective method for improving the magnetocaloric and magnetoelectric properties of GdCrO3.