Tuning the structural, magnetic and optical properties of EuCrO3 orthochromites through Dy3+ substitution

Abstract

In this study, EuCrO₃ (ECO) and Eu_0.9Dy_0.10CrO₃ (EDCO) rare-earth orthochromite compositions were synthesized through the traditional solid-state reaction technique. A comprehensive investigation was conducted to analyse the effect of the substitution of 10 wt% Dy³⁺ ions on the structural, optical and magnetic properties of EuCrO₃. The X-ray diffraction results along with Rietveld refinement confirm the monophasic nature with an orthorhombic distorted perovskite structure for both compositions. Field emission scanning electron microscopy reveals polycrystalline microstructures with average grain sizes ranging from 269 to 327 nm for both compounds. The optical bandgap is evaluated by Tauc’s relation and is observed to slightly increase from 2.24 to 2.33 eV with Dy³⁺ ions substitution. Optical parameters, including skin depth, extinction coefficient, refractive index and optical conductivity are determined and their variations with Dy substitution are analysed. Temperature-dependent magnetic analysis reveals a Néel temperature (T_N) of 177 K in EDCO composition, lower than that of pristine EuCrO₃ (T_N ~181 K). The magnetocaloric effect of the EDCO compound demonstrates a magnetic entropy change (ΔS) and relative cooling power of –0.27 J kg⁻¹ K and 4.4 J kg⁻¹, respectively, near T_N under the application of 7 Tesla field. This study highlights the tunability of EuCrO₃ properties through Dy ion substitution for customized applications.