Chemical pressure-induced structural, optical, and magnetic property transformations of PrAlO3

Progressive substitution of non-magnetic Al3+-ion with magnetic Cr3+-ion in PrAlO3 has been carried out in the present study by preparing the samples using the epoxide mediated sol-gel method. Extensive characterization of these samples was performed to comprehend the effect of chemical pressure on the structure and optical and magnetic properties. The hexagonal system of PrAlO3 with rhombohedral symmetry (R-3c space group) was preserved up to 60 mol % inclusion of Cr3+ in place of Al3+, beyond which the samples exhibited orthorhombic symmetry (Pnma space group). FTIR and Raman's spectra also confirmed the symmetry reduction in these samples. The transitions associated with Pr3+ and Cr3+ ions were observed in the optical spectra. The optical bandgap estimated using Tauc plot decreased from 3.2 (x = 0.10) to 1.75 eV (x = 0.60) in PrAl1-xCrxO3. With higher Cr3+-concentrations, the optical bandgap increased from 1.75 (x = 0.70) to 3.2 eV (PrCrO3). The field dependent magnetic measurements indicated that all the samples were paramagnetic at room temperature and ferromagnetic at 2 K. Inclusion of Cr3+-ion in place of Al3+-ion in PrAlO3 shifts the transition from 109 to 231 K. They resulted in the increased effective magnetic moment.

Automated summary

In this study, progressive substitution of non-magnetic Al3+ ion with magnetic Cr3+ ion in PrAlO3 was carried out. The effects of chemical pressure on the structure, optical, and magnetic properties were investigated. The inclusion of Cr3+ ions led to a reduction in symmetry and a change in the optical bandgap and magnetic behavior of the samples.