  We report on the influence of the improved L21 ordering degree on the
magnetic properties of Co2MnSi Heusler films. Different fractions of the L21
phase are obtained by different post-growth annealing temperatures ranging from
350 degC to 500 degC. Room temperature magneto-optical Kerr effect measurements
reveal an increase of the coercivity at an intermediate annealing temperature
of 425 degC, which is a fingerprint of an increased number of pinning centers
at this temperature. Furthermore, Brillouin light scattering studies show that
the improvement of the L21 order in the Co2MnSi films is correlated with a
decrease of the saturation magnetization by about 9%. The exchange stiffness
constant of Co2MnSi, however, increases by about 8% when the L21 order is
improved. Moreover, we observe a drop of the cubic anisotropy constant K1 by a
factor of 10 for an increasing amount of the L21 phase.
