Signature of ferro–paraelectric transition in biferroic LuCrO₃ from electron paramagnetic resonance and non-resonant microwave absorption

An electron paramagnetic resonance (EPR) study in the polycrystalline biferroic LuCrO₃ is carried out at X-band (8.8–9.8 GHz) in the 295–510 K temperature range. For all the temperatures, the EPR spectra show a single broad line attributable to Cr³⁺ (S = 3/2) ions. The onset of a ferro–paraelectric transition has been determined from the temperature dependence of the parameters deduced from EPR spectra: the peak-to-peak linewidth (ΔH_pp), the g-factor and the integral intensity (I_EPR). Magnetically modulated microwave absorption spectroscopy (MAMMAS) and low-field microwave absorption (LFMA) are used to give further information on this material, where these techniques give also evidence of the ferro–paraelectric transition; indicating a behavior in agreement with a diffuse phase transition. - Highlights: • LuCrO₃ powders are obtained via auto-ignition synthesis. • EPR is employed to study the onset of the ferro–paraelectric transition. • MAMMAS and LFMA techniques are used to give further information on this material