Spin Excitations in Half-Doped Manganites

Abstract

We investigate magnetic excitations in half-doped colossal magnetoresistance manganites. In particular, we focus on spin excitations in the CE phase originally proposed by Goodenough (Phys. Rev. 100:564, 1955). Using a localized spin model, we calculated magnons for 3D-perovskite compounds such as La1−x M x MnO3, where M=Ca, Sr, Ba, and for their 2D-laminar counterparts. We compared them with predictions for the spin excitations corresponding to other phases proposed. For the laminar half-doped manganite La0.5Sr1.5MnO4, for which magnon measurements by inelastic neutron scattering exist, as well as an estimation of the magnetic couplings, our calculations agree well with the experimental data.