Charge States of Cations in Lithium–Nickel Phosphates LiNiPO4 Doped with Manganese and Cobalt

Abstract

Using Ni, Mn, and Co L_2,3-edge soft X-ray absorption spectra supported by calculations of atomic multiplets with allowance for the crystal field and charge transfer, the charge states of cations in doped phosphates LiNiPO₄, LiNi_0.9Co_0.1PO₄, and LiNi_0.9Mn_0.1PO₄ are determined. It is established that nickel, manganese, and cobalt ions are in the divalent high-spin state and have an octahedral oxygen environment. Oxygen K-edge X-ray absorption spectra showed the absence of impurity states in the energy gap of manganese- or cobalt-doped lithium nickel phosphates.