Static and dynamic magnetic properties and effect of surface chemistry on the morphology and crystallinity of DyCrO₃ nanoplatelets

In this contribution, the structural and magnetic properties of DyCrO ₃ nanoplatelets, synthesized by a hydrolytic sol-gel method, have been investigated. The crystalline phase of DyCrO₃ was attained at the decomposition temperature of 800 °C for citric acid and oxalic acid, respectively and their structural analysis indicates a distorted orthorhombic perovskite structure of the DyCrO₃ nanoplatelets. The dc-magnetization curve shows the Néel temperature of ∼144 and ∼146 K for DyCrO₃ nanoplatelets synthesized using citric acid (DCO (C)) and oxalic acid (DCO (O)), respectively. In addition, DCO (O) shows weak anomalies at ∼22 and ∼6 K in the zero-field-cooled and field-cooled magnetization curves. Below the Néel temperature, DCO (C) and DCO (O) exhibit cross-over from positive to negative magnetization at ∼143 and ∼145 K, respectively. This was attributed to a Dy³⁺-Cr ³⁺ interaction, which resulted in a weak ferromagnetic coupling (seen as a small opening in the M-H curves). The low temperature transition observed at ∼6 K can be assigned to the onset of Dy³⁺-Dy³⁺ antiferromagnetic interaction.