Dielectric and optical phonon anomalies near antiferromagnetic ordering in LaCrO3: A possible near room temperature magnetodielectric system

We report on anomalies in the dielectric and optical phonon spectra in bulk orthorhombic distorted perovskite LaCrO3 near an antiferromagnetic transition at 290 K. These anomalies were tracked using temperature dependent (200 K–320 K) dielectric and Raman spectroscopy. We observed a blue-shift for the B3g(3) optical phonon mode coincident with the onset of antiferromagnetic ordering of LaCrO3 in conjunction with a broad dielectric anomaly near the Néel temperature. The dielectric and optical phonon anomalies are discussed in the context of the observed antiferromagnetic transition in temperature dependent magnetic studies.