Electronic structure of KH₂PO₄ single crystal studied by soft-X-ray spectroscopy

The problem of resolving molecular components of the electronic structure of KH₂PO₄ single crystal with respect to its chemical and orbital character has been approached by X-ray absorption spectroscopy (XAS) and soft X-ray emission spectroscopy (SXES). XAS around K-absorption edge of O atom was carried out in order to the existence of relation between the electronic structure and ferroelectric phase transition. Temperature dependence of electronic structure was measured below and above T_C. Obvious differences of electronic structure at phase transition temperature were clearly observed. Density states of electronic structure might be gradually changed due to local distortion of PO₄ tetrahedra.