Observation of Modulated Quadrupolar Structures in PrPb3

TL;DR

This study used neutron diffraction to reveal modulated quadrupolar structures in PrPb3 under magnetic fields, providing evidence for a quadrupolar phase and insights into the behavior of quadrupole moments at low temperatures.

Contribution

First experimental observation of a modulated quadrupolar phase in PrPb3, demonstrating field-dependent quadrupolar ordering and hybridization effects.

Findings

Quadrupolar order appears below 0.4 K at zero field.

Modulated quadrupolar structures vary linearly with magnetic field.

Persistent non-square modulated state exists below 100 mK.

Abstract

Neutron diffraction measurements have been performed on the cubic compound PrPb3 in a [001] magnetic field to examine the quadrupolar ordering. Antiferromagnetic components with q=(1/2+-d 1/2 0), (1/2 1/2+-d 0) (d~1/8) are observed below the transition temperature TQ (0.4 K at H=0) whose amplitudes vary linear with H and vanish at zero field, providing the first evidence for a modulated quadrupolar phase. For H<1 T, a non-square modulated state persists even below 100 mK suggesting quadrupole moments associated with a Gamma3 doublet ground state to be partially quenched by hybridization with conduction electrons.