ELASTIC-CONSTANTS OF ANTIFERROMAGNETIC CHROMIUM

The temperature dependence of the elastic constants of antiferromagnetic chromium in the poly-Q, single-Q and single-S single-Q states has been measured between temperatures a little above the Neel temperature T//N and below the spin-flip temperature. The discontinuities in the elastic constant at T//N agree with the predictions of mean-field theory, and their temperature dependence in the transverse spin density wave phase agree with the predictions of a thermodynamic model, if T//N is assumed to depend mainly on volume strain omega and to be linear in omega .