Magnetic ordering and crystal structure of LiMPO4 compounds with M = (Mn, Fe, Ni/Mn, and Ni/Co)

We present susceptibility, X-ray and neutron diffraction data on powder orthophosphates LiMnPO4, LiFePO4, LiNi0.9Co0.1PO4, and LiNi0.9Mn0.1PO4. Dependences of structure parameters and magnetic state of these compounds on type of 3d element and content of 3d-electrons have been studied. Magnetic moment of 3d-transition ion is orientated along a-axis in LiMnPO4, along b-axis in LiFePO4, and along c-axis in both LiNi0.9Mn0.1PO4 and LiNi0.9Co0.1PO4. At low temperatures, a magnetic moment magnitude is equal to 4.0 μB in LiMnPO4 and LiFePO4 samples, while it is twice less for LiNi0.9Co0.1PO4.