Suppression of the ${\hat{I}}^3-\hat{I}\pm$ structural phase transition in $C{e}_{0.8}L{a}_{0.1}T{h}_{0.1}$ by large magnetic fields

Abstract

The ${\hat{I}}^3-\hat{I}\pm$ transition in Ce${}_{0.8}$La${}_{0.1}$Th${}_{0.1}$ is measured as a function of applied magnetic field using both resistivity and magnetization. The ${\hat{I}}^3-\hat{I}\pm$ transition temperature decreases with increasing magnetic field, reaching zero temperature at around 56 T. The magnetic-field dependence of the transition temperature may be fitted using a model that invokes the field and temperature dependence of the entropy of the $4f$-electron moments of the ${\hat{I}}^3$ phase, suggesting that the volume collapse in Ce and its alloys is primarily driven by entropic considerations.