Anomalous magnetic structure and spin dynamics in magnetoelectric LiFePO4

Research output: Contribution to journalArticlepeer-review

Authors

  • Rasmus Toft-Petersen
  • Manfred Reehuis
  • Thomas B S Jensen
  • Niels H. Andersen
  • Jiying Li
  • Manh Duc Le
  • Christof Niedermayer
  • Bastian Klemke
  • Kim Lefmann
  • David Vaknin

External organisations

  • Helmholtz-Zentrum Berlin für Materialien und Energie (HZB)
  • Technical University of Denmark
  • Iowa State University
  • Institute for Basic Science
  • Paul Scherrer Institut
  • Dept. of Metallurgy and Materials
  • Niels Bohr Institute

Abstract

We report significant details of the magnetic structure and spin dynamics of LiFePO4 obtained by single-crystal neutron scattering. Our results confirm a previously reported collinear rotation of the spins away from the principal b axis, and they determine that the rotation is toward the a axis. In addition, we find a significant spin-canting component along c. The possible causes of these components are discussed, and their significance for the magnetoelectric effect is analyzed. Inelastic neutron scattering along the three principal directions reveals a highly anisotropic hard plane consistent with earlier susceptibility measurements. Using a spin Hamiltonian, we show that the spin dimensionality is intermediate between XY- and Ising-like, with an easy b axis and a hard c axis. It is shown that both next-nearest neighbor exchange couplings in the bc plane are in competition with the strongest nearest neighbor coupling.

Details

Original languageEnglish
Article number024404
JournalPhysical Review B
Volume92
Issue number2
Publication statusPublished - 6 Jul 2015