Pressure induced structural phase transition and magneto-elastic coupling in Eu doped LaCrO$_3$

RESUMO

In this study, we have carried out a detailed high pressure investigation on 5$\%$ Eu doped LaCrO$_3$ (ELCO) using synchrotron X-ray diffraction (XRD), micro Raman spectroscopy, and low-temperature magnetization measurements to correlate the structural and magnetic properties under pressure. The high pressure XRD reveals the orthorhombic to rhombohedral structural phase transition around 10.6 GPa. The high pressure Raman data corroborate this result and indicate that the lattice instabilities associated with the low-frequency soft modes play a crucial role in driving this transition. In addition, a pronounced anomaly in the Raman shift and integrated intensity of several Raman modes is observed around 4.5 GPa. By combining the low-temperature magnetization measurements with the anomalies observed in the XRD and Raman data and by comparing with the similar results in LaCrO$_3$ (LCO), a pressure-induced change in the magnetic ground state to antiferromagnetic ordering is predicted.