Raman analysis and crystal structure of polycrystalline LiNi1−xCoxPO4 (x = 0–0.5)

Models of Ni- and Co-ion occupation in LiNi0.5Co0.5PO4 orthophosphate and its magnetic structure

“…The resulting powder was annealed twice at temperatures of 800 • C and 900 • C in air for 12 h with intermediate grinding in ethanol, followed by cooling of the sample to room temperature. The quality of the synthesized sample has been confirmed by x-ray diffraction with the Shimadzu XRD 700 high-resolution x-ray diffractometer using a Bragg-Brentano geometry with a Cu K α1,2 source at 298 K. At room temperature a refined parameters of the crystal structure LiNi 0.5 Co 0.5 PO 4 and their Rietveld analysis are given in our previous work [18].…”

“…Equation ( 3) was fitted to the experimental points measured above 45 K, because for these temperatures, C l is the only significant contribution to the specific heat. When fitting, energies of third optical modes, selected from Raman measurements determined in our previous work [18] as the most influencing the temperature dependence of specific heat, were taken as known parameters, whereas Θ D , n D , n i , and α were fitted.…”

“…In the crystal structure of LiMPO 4 the A-site (Li + and M 2+ ) cations occupy 4a and 4c Wyckoff positions, which are surrounded by oxygen anions in the LiO 6 and MO 6 octahedrons. The B-site (P 5+ ) cation occupying the 4c Wyckoff position is surrounded by oxygen anions in the PO 4 tetrahedron [18].…”