  We investigate the dynamics and outcome of a quantum phase transition from an
antiferromagnetic to phase separated ground state in a spin-1 Bose-Einstein
condensate of ultracold atoms. We explicitly demonstrate double universality in
dynamics within experiments with various quench time. Furthermore, we show that
spin domains created in the nonequilibrium transition constitute a set of
mutually incoherent quasicondensates. The quasicondensates appear to be
positioned in a semi-regular fashion, which is a result of the conservation of
local magnetization during the post-selection dynamics.
