Field-Induced Magnetic Order and Simultaneous Lattice Deformation in TlCuCl3

TL;DR

This study investigates how magnetic fields induce antiferromagnetic order in TlCuCl3, revealing that this transition is accompanied by lattice deformation, as shown by NMR and thermal expansion measurements.

Contribution

It provides experimental evidence of simultaneous magnetic ordering and lattice deformation in TlCuCl3 under magnetic fields, highlighting the coupling between magnetic and structural properties.

Findings

Field-induced antiferromagnetic transition is slightly discontinuous.

Magnetic order is accompanied by lattice deformation.

Electric field gradient changes abruptly at phase boundary.

Abstract

We report the results of Cu and Cl nuclear magnetic resonance experiments (NMR) and thermal expansion measurements in magnetic fields in the coupled dimer spin system TlCuCl3. We found that the field-induced antiferromagnetic transition as confirmed by the splitting of NMR lines is slightly discontinuous. The abrupt change of the electric field gradient at the Cl sites, as well as the sizable change of the lattice constants, across the phase boundary indicate that the magnetic order is accompanied by simultaneous lattice deformation.