First-principles investigation of the structural, magnetic, and electronic properties of olivine LiFePO4 -: art. no. 144404

We present a first-principles investigation of the structural, magnetic, and electronic properties of LiFePO4 olivine. The ground-state antiferromagnetic spin arrangement consistent with a superexchange mechanism through oxygen orbits is found to be preferred, showing an antiferromagnetic order between corner sharing octahedra along the [010] direction. This is in agreement with an oxygen-mediated superexchange mechanism for the iron-iron magnetic interaction. The theoretical Neel temperature estimated by a mean-field approximation is in the range between 33.1 K and 53.5 K, in acceptable agreement with the experimental susceptibility measurement, which gives T-N=52 K. The calculated magnetic moment of 3.72 mu(B) is close to the value of 4 mu(B) deduced from the ionic model according to the Hund's rule.