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 (ΔHpp), the g-factor and the integral intensity (IEPR). 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.