  The effect of substitution of Co and Fe for Ni in TbNi5 on the structural,
magnetic and magneto-thermal properties has been investigated. Considerable
enhancement of Curie temperature is observed with Fe substitution, whereas the
increase is nominal in the case of Co. Neutron diffraction measurements reveal
the redistribution of moments and site preference of substitutional ions in Ni
2c and 3g sites. In TbNi4Fe, both Ni and Fe as well as Tb are found to carry
moment while in the case of TbNi4Co, mainly Tb carries the moment.
Magnetocaloric behavior has been investigated from the magnetization and the
heat capacity measurements. The magnetic and magnetocaloric properties are
found to be strongly correlated in these compounds.
