Weak ferromagnetism in the magnetoelectric detected by microwave power absorption measurements

An electron paramagnetic resonance (EPR) study in polycrystalline magnetoelectric Y CrO3 is carried out at the X-band (8.8–9.8 GHz) in the 85–300 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 the antiferro–paramagnetic transition has been determined from the temperature dependence of parameters deduced from the EPR spectra: the integrated intensity ( I E P R ), the g-factor and the peak-to-peak linewidth ( Δ H p p ). Below 140 K, a weak ferromagnetism is observed and it is attributed to canting of Cr3+ ion sublattices in the antiferromagnetic matrix. Low-field microwave absorption (LFMA) is used to give further knowledge on this material; where this technique also gives evidence of the magnetic order, suggesting a weak ferromagnetism at low temperature.