  A coupled spin-electron chain composed of localized Ising spins and mobile
electrons is exactly solved in an external magnetic field within the
transfer-matrix method. The ground-state phase diagram involves in total seven
different ground states, which differ in the number of mobile electrons per
unit cell and the respective spin arrangements. A rigorous analysis of the
low-temperature magnetization process reveals doping-dependent magnetization
plateaus, which may be tuned through the density of mobile electrons. It is
demonstrated that the fractional value of the electron density is responsible
for an enhanced magnetocaloric effect due to an annealed bond disorder of the
mobile electrons.
