Some aspects of antiferromagnetic ordering in LiMnP0.85V0.15O4: Neutron diffraction and DC-magnetization studies

Effect of vanadium doping on the magnetic properties of LiMnPO4

“…At sufficiently high temperatures ( T > 70 K), the antiferromagnetic interactions obviously dominate. This is evidenced by the negative Weiss constant obtained by fitting of the experimental susceptibility of the paramagnetic phase of pure and V‐doped LiMnPO 4 (−64 ÷ −81 K – this work, −78 K , −87 K ). However, there are not only antiferromagnetic, but also ferromagnetic interactions directed along the b ‐ and c ‐axes (Fig.…”

“…The XRD patterns of pure LiMnPO 4 (V‐0), V‐doped LiMnPO 4 (V‐0.15) – see details in Ref. , and V‐doped LiMnPO 4 treated in the hydrogen atmosphere (V‐0.1H) – see details in Ref. .…”

“…This is caused by the fact that the radius of P 5+ is much smaller than those of V 5+ and V 4+ (IR P = 0.17 Å, IR V5+ = 0.355 Å, IR V4+ = 0.53 Å ). We compare the vanadium ions with phosphorus, but not with manganese ions as vanadium was shown to substitute for tetrahedral P rather than for octahedral Mn . The results of Rietveld refinement of the neutron data are listed in Table .…”

“…The antiferromagnetic phase of pure and doped Li‐Mn‐phosphate belongs to the magnetic space group Pn′m′a′ (No. 449.62) . There are four magnetic atoms in the unit cell: Mn1 ( x , ¼, z ); Mn2 (, ¾, ); Mn3 (½ – x , ¾, ½ + z ); and Mn4 (½ + x , ¼, ½ – z ), with the moments parallel to the a ‐axis (Fig.…”

“…The allocation of vanadium in LiMnPO 4 was investigated using a number of diffraction and spectral methods , which like the results of the ab initio calculations , clearly indicated that the vanadium atoms in the vanadium‐substituted LiMnPO 4 indeed occupy the phosphorus sites. Vanadium is an element with variable valence.…”