  The tetragonal layered compounds TbTiGe and ErTiGe order
antiferromagnetically at 276 K and 39 K, respectively. Partial substitution of
Mo for Ti in these two compounds modifies the magnetic interactions giving rise
to a ferromagnetic ground state which results in an enhanced magnetocaloric
effect. The magnetic entropy change in ErTi0.85Mo0.15Ge for a magnetic field
change of 5 T is ~10.5 J/kg/K against ~0.8 J/kg/K for ErTiGe in the vicinity of
the magnetic transition. Thus, magnetocaloric properties of such layered
materials may be tunable by suitable chemical substitutions.
