Influence of europium doping on conductivity of LiNiPO4
(1. Department of Metallurgical Engineering and Material Science, Indian Institute of Technology Bombay,
Mumbai, India;
2. Department of Physics, Kalasalingam University, Krishnankoil-626126, Tamilnadu, India;
3. School of Advanced Sciences, VIT University, Vellore 632014, Tamilnadu, India;
4. Department of Physics, Alagappa University, Karaikudi-630003, Tamilnadu, India)
Mumbai, India;
2. Department of Physics, Kalasalingam University, Krishnankoil-626126, Tamilnadu, India;
3. School of Advanced Sciences, VIT University, Vellore 632014, Tamilnadu, India;
4. Department of Physics, Alagappa University, Karaikudi-630003, Tamilnadu, India)
Abstract: Europium doped LiNiPO4 and undoped LiNiPO4 were prepared by Pechini method. Compound formation temperature was confirmed from thermogravimetry and differential thermal analysis (TG/DTA). Powder X-ray diffraction (XRD) pattern confirmed the formation of pure LiNiPO4 compound with an orthorhombic structure. The conductivity and modulus analyses of the samples were carried out at different temperatures and frequencies using the complex impedance spectroscopy technique. The conductivity parameters such as ion hopping frequency and the charge carrier concentration term were calculated using Almond and West formalisms. An increase of one order of magnitude in the ionic conductivity has been observed for 1.0% Eu-doped LiNiPO4. (mole fraction). The complex modulus studies suggest the presence of non-Debye type of relaxation in the materials.
Key words: LiNiPO4; ionic conductivity; impedance spectroscopy; doping; hopping