Effect of Mg doping on the electrical, dielectric and relaxation properties of LiMnPO₄ nanoparticles

LiMnPO₄ and LiMn_0.9Mg_0.1PO₄ nanostructures were synthesized by a rapid microwave-assisted solvothermal method. Powder X-ray diffraction (XRD) studies confirmed the orthorhombic crystal structure of LiMnPO₄ and LiMn_0.9Mg_0.1PO₄ nanostructures. It is also noticed that the Mg²⁺ ions doping into manganese sites did not affect the crystal structure of LiMnPO₄. The scanning electron microscope (SEM) micrographs of LiMnPO₄ and LiMn_0.9Mg_0.1PO₄ showed the formation of nanoparticles with mixed morphology, i.e., spherical particle morphology and one-dimensional nanorod morphology. The LiMn_0.9Mg_0.1PO₄ nanoparticles exhibited an improved electrical properties compared to that of LiMnPO₄ nanoparticles. At room temperature, LiMn_0.9Mg_0.1PO₄ nanoparticles exhibited an electrical conductivity of 3.705×10-7 S cm−1. The dielectric constant of LiMnPO₄ and LiMn_0.9Mg_0.1PO₄ nanostructures is high at low frequencies and decreases gradually towards high frequencies. The LiMnPO₄ and LiMn_0.9Mg_0.1PO₄ nanostructures are found to exhibit non-Debye-type relaxation behavior. (author)