The temperature dependence of the Cd hyperfine field in a trivacancy c
omplex in Ni between 25 and 300 K is reported. It was found that, unli
ke the Cd substitutional field in Ni which follows the temperature dep
endence of the magnetization, the Cd hyperfine field in a trivacancy c
omplex is essentially temperature independent. This temperature anomal
y is compared with other temperature anomaly of impurity hyperfine fie
lds in ferromagnetic hosts.