Anomalous in-plane magnetoresistance in a EuFe2As2 single crystal: Evidence of strong spin-charge-lattice coupling

作者：Xiao Y^*; Su Y; Nandi S; Price S; Schmitz B; Kumar C M N; Mittal R; Chatterji T; Kumar N; Dhar S K; Thamizhavel A; Brueckel Th

来源：Physical Review B, 2012, 85(9): 094504.

DOI：10.1103/PhysRevB.85.094504

In-plane magnetotransport properties of a EuFe2As2 single crystal are investigated by angular-dependent magnetoresistance (MR) measurements. Strong anisotropy in magnetotransport properties is observed below the magnetic ordering temperature and it exhibits intimate correlations with the ordering states of both Eu2+ and Fe2+ spins as well as the twinned structure in EuFe2As2 crystal. Such correlations lead to giant MR effect around the magnetic phase boundary, e.g., negative MR of similar to 26% is observed at 5 K and 1 T upon the reorientation of Eu2+ spins from antiferromagnetic to ferromagnetic configuration. Compared with Eu2+ moments, Fe2+ moments with antiferromagnetic arrangement generated relatively weak effect on MR due to its small ordered moment. All obtained MR results can be well understood based on the scenario of superzone boundary effect and the electron scattering by fluctuation of spins and twinning boundaries. It also suggests that the magnetic order state plays an important role for the determination of transport properties through the strong coupling between itinerant electrons and ordered spins.

• 出版日期2012-3-5