Helical magnetic ordering in Tb completely suppressed by uniaxial tension: Evidence of electronic topological transition and support for the nesting hypothesis

A single crystal of Tb was examined under uniaxial tension applied along the hexagonal axis by means of magnetic susceptibility vs temperature. The temperature range within which helical ordering occurs was determined from χ(T) curves. This range diminishes rapidly as uniaxial tension is applied, and at tensions over p*=680 bar the helical ordering is completely suppressed. The experiment supports the hypothesis that the type of magnetic ordering in rare-earth metals is determined by Fermi surface topology, which can in turn be altered by uniaxial deformation.