Neutron Scattering Measurements in Chromium near the Néel Temperature

抄録

Magnetic excitations in chromium near the Néel temperature were investigated using a neutron time-of-flight spectrometer. Above T_N, the excitation was analyzed following the paramagnon model. The Fermi velocity v_F is estimated to be v_F=2.7(±1.3)×10⁷ cm/sec at 1.105 T_N in good agreement with the theoretical value. The integrated intensity of scattered neutrons displayed a maximum at 313 K and rapidly decreased as the temperature became lowered. The renormalization of spin wave velocity and the longitudinal spin fluctuation model are proposed as possible explanations.