Raman measurements of temperature dependencies of phonons in LiMnPO4

摘要: Abstract We present results of Raman and infrared absorption spectroscopy research on phonons in LiMnPO 4 —a new material for high capacitance rechargeable lithium-ion batteries. There is a significant interest the structural electrical properties this material, because battery performance depends strongly rate lithium diffusion. Nanopowder was obtained via modified sol–gel method from salts manganese. This cheap effective so it promising most popular applications. The showed sharp phonon peaks spectra. In spectra, strongest peak A g ν 1 mode at energy 117.77 meV (950.1 cm −1 ), 4 K. At room temperature, its decreased (due to phonon–phonon interaction) 117.5 meV (947.5 cm ). Gruneisen parameter found oscillation relatively low, γ = 0.5 , about 300 K. Since consisted mainly symmetric PO tetrahedra oscillations, low value indicated that temperature influenced rather Li–O Mn–O bonds than P–O forming structure. thermal dependencies antisymmetric modes (A 3 ) were stronger ( 0.7 1.4 what suggested these experienced coupling. broadening could be described wide range by exponential dependence with activation 65 meV (about two times smaller energy), two-phonon decay.