  Low-temperature magnetization processes and magnetocaloric properties of a
geometrically frustrated spin-1 Blume-Capel model on a triangular lattice are
studied by Monte Carlo simulations. The model is found to display qualitatively
different behavior depending on the sign of the single-ion anisotropy D. For
positive values of D we observe two magnetization plateaus, similar to the
spin-1/2 Ising antiferromagnet, and negative isothermal entropy changes for any
field intensity. For a range of small negative values of D there are four
magnetization plateaus and the entropy changes can be either negative or
positive, depending on the field. If D is negative but large in absolute value
then the entropy changes are solely positive.
