Structural, vibrational, magnetic, and dielectric properties of hexagonally ordered Cr-doped LuMn_1 − xCr_xO₃ (0 ≤ x ≤ 0.08) manganite

This study examines how controlled doping of trivalent cations (Cr³⁺) at manganese (Mn³⁺) sites influences the structural, microstructural, vibrational, magnetic, and dielectric properties of LuMn_1 − xCr_xO₃ (0 ≤ x ≤ 0.08) compounds. These compounds were synthesized using conventional solid-state reaction techniques. Rietveld-fitted X-ray diffraction reveals hexagonal crystal symmetry (P₆₃cm space group) with reduced lattice parameters and volume due to Cr doping and ionic size mismatch. Room temperature Raman spectra show phonon peak shifts and reduced mode intensity, indicating structural disorder or internal stress in all samples. The magnetization outcomes reveal a weak ferromagnetic property across all samples, which can be enhanced with higher concentrations of Cr ions. The frequency-dependent dielectric properties and loss tangent (tan δ) at 300 K in all examined compounds demonstrate a decrease in dielectric constant and an increase in loss tangent. These changes are attributed to the double exchange interaction between Mn³⁺-O-Cr³⁺ cations, supported by the metallic character’s emergence. Our findings on improved magnetization and adjusted dielectric parameters represent progress in understanding multiferroic compounds.