First-order phase transitions in Tb, Dy, and Ho

Abstract
A renormalization-group analysis suggests that the paramagnetic-to-helical phase transitions in Tb, Dy, and Ho are of first order; this result is in disagreement with the conclusions and assumptions of previous experimental and theoretical papers. Results for the order of the phase transitions in TbAu2, DyC2, and stressed Cr and Eu are also given.