  We report a large and unexpected suppression of the free electron spin
relaxation in lightly-doped n-GaAs bulk crystals. The spin relaxation rate
shows weak mobility dependence and saturates at a level 30 times less then that
predicted by the Dyakonov-Perel theory. The dynamics of the spin-orbit field
differs substantially from the usual scheme: although all the experimental data
can be self-consistently interpreted as a precessional spin relaxation induced
by a random spin-orbit field, the correlation time of this random field,
surprisingly, is much shorter than, and is independent of, the momentum
relaxation time determined from transport measurements. Understanding of this
phenomenon could lead to high temperature engineering of the electron spin
memory.
