We have investigated the effect of hydrostatic pressure on magnetic properties of TbNiAl, crystallizing in hexagonal ZrNiAl-type structure. TbNiAl orders antiferromagnetically below T-N = 4 5 K and undergoes further magnetic phase transition to another AF phase at T-1 = 23 K.
The magnetic field of B-c congruent to 0.3 T applied along the c-axis at 2 K leads to the transition to ferromagnetic order. By applying the hydrostatic pressure, both T-N and T-1 remain almost unaffected whereas B-c shows a strong increase.
The hydrostatic pressure stabilizes the antiferromagnetic state which can be related to development of structural parameters.