We have generated magnetization in antiferromagnetic MnF2 by selectively pumping the lowest A16→T14 sublattice excitons (or exciton-magnon band) with a pulsed, tunable dye laser. Intersublattice relaxation processes were studied by observing the creation and decay of specific excitations, as induction signals. The exciton relaxation time decreases with increasing temperature and pumping power. We interpret this as intersublattice relaxation assisted by thermally excited magnons. © 1971 The American Physical Society.