  Low-temperature magnetization curves and thermodynamics of a spin-1/2
Heisenberg octahedral chain with the intraplaquette and monomer-plaquette
interactions are examined within a two-component lattice-gas model of hard-core
monomers, which takes into account all low-lying energy modes in a highly
frustrated parameter space involving the monomer-tetramer, localized
many-magnon and fully polarized ground states. It is shown that the developed
lattice-gas model satisfactorily describes all pronounced features of the
low-temperature magnetization process and the magneto-thermodynamics such as
abrupt changes of the isothermal magnetization curves, a double-peak structure
of the specific heat or a giant magnetocaloric effect.
