PROGRESS TOWARDS PRODUCING A MONODOMAIN IN THE CHARGE-DENSITY-WAVE STATE OF ALPHA-URANIUM

The charge-density-wave (CDW) in elemental uranium is known to contain propagation vectors along all three principal crystallographic direct ions, i.e. all of q(x), q(y), and q(z) are non-zero. Neglecting time r eversal, this allows for 4 possible combinations, and thus possible q vectors. Theory has predicted that these are coupled in pairs so that the CDW state contains two different domains, each one being a 2-q sta te. Neutron-diffraction experiments with uniaxial stress have verified these predictions for the first time, and give further information re lative to the weak incommensurate scattering arising from the boundary regions between the domains.