Abstract
We report elastic and inelastic neutron scattering measurements of the high-TC ferromagnet
Mn(1+delta)Sb. Measurements were performed on a large, TC = 434 K, single crystal with interstitial
Mn content of delta=0.13. The neutron diffraction results reveal that the interstitial Mn has a magnetic moment, and that it is aligned antiparallel to the main Mn moment. We perform density
functional theory calculations including the interstitial Mn, and find the interstitial to be magnetic
in agreement with the diffraction data. The inelastic neutron scattering measurements reveal two
features in the magnetic dynamics: i) a spin-wave-like dispersion emanating from ferromagnetic
Bragg positions (H K 2n), and ii) a broad, non-dispersive signal centered at forbidden Bragg positions
(H K 2n+1). The inelastic spectrum cannot be modeled by simple linear spin-wave theory
calculations, and appears to be significantly altered by the presence of the interstitial Mn ions. The
results show that the influence of the int
