The effect of uniaxial compressive stress on the Neel transition in chromium

The stress dependence of the Neel temperature T N of chromium, which is detected by means of the ultrasonic attenuation peak at the first-order transition, is measured for compressive stress sigma along a (100) and a (110) axis. It is found to be isotropic within the experimental accuracy, having a value of dT Z N/d sigma =-1.5+or-0.4K kbar -1 . Both ultrasonic and neutron scattering measurements fail to reveal the expected approach to a tricritical point for sigma along (110) because of irreversible broadening of the transition at values of sigma of the order of 100 bar.