Impedance spectroscopy and conduction mechanism of LiAlP2O7 material

LiAIP(2)O(7) compound has been obtained by standard solid-state reaction technique and found to crystallize in the monoclinic system with P2(1/a) space group. The impedance plots are well fitted to two equivalent circuit models. The dc conductivity follows Arrhenius behavior with two different activation energies Ea (I) = 0.84 eV for T < 610 K and Ea(II) = 0.93 eV for T > 610 K. Actually, the values of activation energies obtained from the dc conductivity and the relaxation frequency are similar, and hence the transport in the titled compound can be described through a hopping mechanism, dominated by the motion of Li+ ions. Besides, the frequency dependence of the conductivity is interpreted in terms of Jonscher's law. The NSPT model and the CBH model is the most applicable conduction mechanism in region (I) and (II), respectively. The ion transport is due to the hopping of Li+ ions along [100] tunnels direction. The conduction mechanism is studied with the help of Elliot's theory, and the Elliot's parameters are determined. (C) 2016 Elsevier Ltd. All rights reserved.