Crystal structure, thermal properties, and magnetic properties were studied systematically in ${\mathrm{Y}}_{1-x}\mathrm{P}{\mathrm{r}}_x\mathrm{Cr}{\mathrm{O}}_3$ with $0.0\le x\le 0.3$ compositions. Magnetic susceptibility and specific-heat measurements show an increase in the antiferromagnetic transition temperature $\left(T_N\right)$ as Pr is substituted in the Y sites and notable magnetic features are observed below $T_N$. Strong coupling between magnetic and crystalline parameters is observed in a small range of Pr compositions. A small perturbation in the lattice parameters by a Pr ion is sufficient to induce a spin-reorientation transition followed by magnetization reversal to finally induce the exchange-bias effect. The spin-reorientation temperature $\left(T_{\mathrm{SR}}\right)$ is increased from 35 to 149 K for $0.025\le x\le 0.1$ compositions. It is found that the Cr spin sublattice rotates continuously from $T_{\mathrm{SR}}$ to a new spin configuration at lower temperature. In addition, magnetization reversal is observed at $T^{*}\sim 35\mathrm{K}$ for $x=0.05$ up to $T^{*}\sim 63\mathrm{K}$ for $x=0.20$ composition. The $M\text{−}H$ curves show a negative exchange-bias effect induced by Pr ions, which are observed below 100 K and are more intense at 5 K. At 10 K, the magnetic contribution of the specific heat as well as the ZFC magnetization show the rise of a peak with increasing Pr content. The magnetic anomaly could be associated with the freezing of the Pr magnetic moment randomly distributed at the $4c$ crystallographic site. A clear correspondence between spin reorientation, magnetization reversal, and exchange-bias anisotropy with the tilting and octahedral distortion is also discussed.

• Received 15 February 2017
• Revised 4 October 2017

DOI:https://doi.org/10.1103/PhysRevMaterials.2.014409