arXiv subjects

Peter Liermann

Publications and source records attributed to Peter Liermann.

2 recordsLinked to original sources

arXiv2026

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

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.

cond-mat.str-el↗

arXiv2025

Pressure induced ferromagnetic to antiferromagnetic phase transition in transition metal chalcogenide Cr$_{3}$Te$_4$

We have carried out a detailed high-pressure investigation on the strongly correlated transition metal chalcogenide $Cr_{3}Te_4$ using Raman spectroscopy and XRD, which is ferromagnetic and metallic at ambient conditions. We find that the monoclinic structure remains stable up to 30 GPa, the highest pressure studied. The Cr-Te bond length and octahedral volume decrease drastically up to 7.6 GPa pressure. The $A_{1g}$ Raman mode shows a red shift up to 7.6 GPa, and the $E_g$ Raman mode shows a sudden drop around the same pressure. Further low-temperature Raman spectroscopic investigation shows that the Raman modes soften at the ferromagnetic to antiferromagnetic phase transition. This suggests a change in the magnetic ordering at high pressure. Our Density Functional Theory (DFT) calculations reveal the change in magnetic ground state from ferromagnetic state to antiferromagnetic state above 7.6 GPa pressure, corroborating our experimental result.

cond-mat.str-el↗