The elastic constants of chromium

Abstract

Measurements have been made of the three single-crystal elastic stiffness constants of chromium from 4·2°K to 345°K using an ultrasonic pulse-echo technique. The compressional constants C ₁₁ and C ₁₂ show large anomalies at the antiferromagnetic Néel temperature T _N=311°K, and much smaller anomalies at the spin-flip temperature, T _SF=123°K. The shear constants C ₁₁–C ₁₂ and C ₄₄ show rather small anomalies at T _N but there are large changes at T _SF. Between T _SF and T _N all the elastic constants are magnetic field dependent and the anomalous behaviour may be understood, in principle, in terms of a stress-induced movement of antiferromagnetic domain boundaries.