New Aspects of the Temperature-Magnetic Field Phase Diagram of CeB6

TL;DR

This study explores the complex magnetic and quadrupolar phase diagram of CeB6 under high magnetic fields, revealing re-entrant phase behavior and characterizing the nature of its zero-field transition.

Contribution

It provides detailed high-field measurements of CeB6, uncovering re-entrant phase lines and clarifying the nature of its zero-field phase transition.

Findings

Re-entrant phase separation line above 35 T

Zero-field transition to a non-dipolar ordered state

Second order transition signatures in sound and heat measurements

Abstract

We have measured the magnetic field dependence of the paramagnetic to the field-induced high temperature antiferroquadrupolar magnetically ordered phase transition is CeB6 from 0 to 60 T using a variety of techniques. It is found that the field-dependent phase separation line becomes re-entrant above 35 T and below 10 K. Measurements of resonant ultra-sound, specific heat and neutron diffraction show conclusively that the zero-field temperature-dependent phase transition is to a state with no ordered dipole moments, but with second order transition signatures in both sound attenuation and specific heat.