Title: Pressure induced spin crossover in disordered α-LiFeO2,
Abstract: Structural, magnetic and electrical-transport properties of {\alpha}-LiFeO2,
crystallizing in the rock salt structure with random distribution of Li and Fe
ions, have been studied by synchrotron X-ray diffraction, 57Fe Mössbauer
spectroscopy and electrical resistance measurements at pressures up to 100 GPa
using diamond anvil cells. It was found that the crystal structure is stable at
least to 82 GPa, though a significant change in compressibility has been
observed above 50 GPa. The changes in the structural properties are found to be
on a par with a sluggish Fe3+ high- to low-spin (HS-LS) transition (S=5/2 to
S=1/2) starting at 50 GPa and not completed even at ~100 GPa. The HS-LS
transition is accompanied by an appreciable resistance decrease remaining a
semiconductor up to 115 GPa and is not expected to be metallic even at about
200 GPa. The observed feature of the pressure-induced HS-LS transition is not
an ordinary behavior of ferric oxides at high pressures. The effect of Fe3+
nearest and next nearest neighbors on the features of the spin crossover is
discussed.