Subtle Structural Changes in LaFeO3 at High Pressure.

High‐pressure neutron diffraction measurements of polycrystalline LaFeO3 are collected up to 5.5 and 6.4 GPa at 290 and 110 K, respectively. The bulk moduli are determined as B0(290 K) = 170(3) GPa and B0(110 K) = 175(1) GPa. The unit cell is found to compress anisotropically at both temperatures with the a‐axis compressing preferentially. A crossover in lattice parameters is observed, from a > c to c > a, at 2 GPa at 290 K and at 1.7 GPa at 110 K. The magnetic moment remains unchanged over the pressure range investigated, with a value of 4.4 μB and 4 μB at 110 and 290 K, respectively. Analysis of the octahedral tilting angles and the spontaneous lattice strains shows an increased orthorhombic distortion with pressure, but shows no trend toward a change in symmetry. High‐pressure Raman spectroscopy measurements at room temperature are in agreement with the diffraction data. [ABSTRACT FROM AUTHOR]