Magnetocaloric Effect of the $Tb_{1-x}Y_{x}NiAl$ and $TbNiAl_{1-y}In_{y}$ Series

We have studied the development of the magnetocaloric effect in the (Tb,Y)NiAl and TbNi(Al,In) series as determined from magnetization measurements. The transition from antiferromagnetic order in TbNiAl to ferromagnetic order in $Tb_{0.7}Y_{0.3}NiAl$ is accompanied by increase of the maximum entropy change from - 4.1 to - 4.4 J $kg^{-1} K^{-1}$. In the TbNi(Al,In) series, the change of uniaxial anisotropy in TbNiAl to the easy-plane anisotropy in TbNiIn leads to broadening of the magnetocaloric effect accompanied with large increase of the relative cooling power from 66 to 120 J $kg^{-1}$.