  We present dynamic nuclear polarization (DNP) in the simplest pseudospin
quantum Hall ferromagnet (QHF) of an InSb two-dimensional electron gas with a
large g factor using tilted magnetic fields. The DNP-induced amplitude change
of a resistance spike of the QHF at large current enables observation of the
resistively detected nuclear magnetic resonance of the high nuclear spin
isotope 115In with nine quadrupole splittings. Our results demonstrate the
importance of domain structures in the DNP process. The nuclear spin relaxation
time T1 in this QHF was relatively short (~ 120 s), and almost temperature
independent.
