Structural, magnetic, and electrochemical properties of LiMn1−xNixPO4

Abstract A solid solutions series of LiMn 1− x Ni x PO 4 nanomaterials with 0 ≤  x  ≤ 0.45 was produced by a low-temperature microwave-assisted hydrothermal process. The materials have been systematically studied regarding structure, morphology, magnetism, and electrochemical properties. The lattice parameters in the orthorhombic olivine structure obey Vegard's law and linearly depend on x . Similarly, the static magnetisation reflects the decrease of the transition metal paramagnetic moment upon substitution of Mn 2+ by Ni 2+ . At low temperatures, antiferromagnetic long range order appears for all Ni-concentrations. The potential of the Mn 2+/3+ redox couple is found to linearly increase with x . This is explained by a larger electronegativity of Ni 2+ as compared to Mn 2+ and associated changes in the covalency of the Mn O bond.