Pressure-induced phase transition in LaCo5 studied by x-ray emission spectroscopy, x-ray diffraction, and density functional theory

摘要

The pressure dependences of the electronic and crystal structures of LaCo5 have been studied with high-resolution x-ray absorption spectroscopy (XAS) and x-ray diffraction comprehensively. The lattice constant ratio of a/c shows an anomaly around 12-18 GPa without change in the lattice symmetry. In the XAS spectra with partial fluorescence mode as well as in the integrated absolute difference values of the Co K beta emission spectra, a change in the electronic structure was found at around a similar pressure range as the lattice constant anomaly. Density functional theory calculations confirm the presence of a magnetic anomaly around the same pressure region. No temperature dependence of the electronic structure for LaCo5 and YCo5 was observed.