Paramagnetic spin correlations in colossal magnetoresistive La0.7Ca0.3MnO3...

Neutron spectroscopy measurements reveal dynamic spin correlations throughout the Brillouin
zone in the colossal magnetoresistive system La0.7Ca0.3MnO3 at 265 K (1.03 TC). The longwavelength
behavior is consistent with spin diffusion, yet an additional and unexpected component
of the scattering is also observed in low-energy constant-E measurements which takes the form of
ridges of strong scattering running along (H 0 0) and equivalent directions. Well defined Q-space
correlations are observed in constant-E scans at energies up to at least 28 meV, suggesting robust
short-range spin correlations in the paramagnetic phase.