Publication Type
Journal
Journal Name
Physical Review Letters
Publication Date
Page Number
047204
Volume
96
Issue
4
Abstract
Neutron scattering results are presented for spin-wave excitations of three ferromagnetic metallic A1xA0xMnO3 manganites (where A and A0 are rare- and alkaline-earth-metal ions), which when combined with previous work elucidate the systematics of the interactions as a function of carrier concentration x,
on-site disorder, and strength of the lattice distortion. The long-wavelength spin dynamics show only a very weak dependence across the series. The ratio of fourth to first neighbor exchange (J4=J1) that controls the zone boundary magnon softening changes systematically with x, but does not depend on the other parameters. None of the prevailing models can account for these behaviors.
