Low temperature magnetostriction studies in CsNiCl3

The forced magnetostriction of the linear-chain antiferromagnet CsNiCl₃ has been measured from 1.6 to 20K. For the applied field parallel to the c-axis the data below the Néel temperature T_N clearly show the effects of the spin-flop near 20 kG. Effects ascribed to domain realignment are observed below 5 kG for the field normal to the c-axis. In the paramagnetic phase above T_N the magnetostrictive behavior conforms to a simple model in which the intrachain exchange J is a function only of the c-parameter. The resulting partial Grüneisen parameter $\text{γ∥}{}^{\mathrm{m}}\text{=}\text{?d(?nJ)}\text{d(?nc)}$ is compared with that obtained from thermal expansion measurements.