  We investigate the dynamics of a F=1 spinor Bose-Einstein condensate of 87Rb
atoms confined in a quasi-one-dimensional trap both at zero and at finite
temperature. At zero temperature, we observe coherent oscillations between
populations of the various spin components and the formation of multiple
domains in the condensate. We study also finite temperature effects in the spin
dynamics taking into account the phase fluctuations in the Bogoliubov-de Gennes
framework. At finite T, despite complex multidomain formation in the
condensate, population equipartition occurs. The length scale of these spin
domains seems to be determined intrinsically by nonlinear interactions.
