The temperature dependence of the four Raman-active phonons in NiF2 has been investigated
at temperatures above and below the antiferromagnetic ordering temperature of
TN=73 K. All four modes exhibit distinct anomalies in their intensities and frequencies near TN due to spin-phonon coupling. The phonon linewidths also exhibit weak anomalies. From
the temperature dependences of the phonon frequencies, estimates are made of the spin-phonon coupling coefficients. The B1g phonon exhibits anomalous mode softening with
decreasing temperature from 300 K to TN .