Magnetoelastics of a spin liquid: X-ray diffraction studies of Tb ₂Ti₂O₇ in pulsed magnetic fields

We report high resolution single crystal x-ray diffraction measurements of the frustrated pyrochlore magnet Tb₂Ti₂O₇, collected using a novel low temperature pulsed magnet system. This instrument allows characterization of structural degrees of freedom to temperatures as low as 4.4 K, and in applied magnetic fields as large as 30 T. We show that Tb ₂Ti₂O₇ manifests intriguing structural effects under the application of magnetic fields, including strongly anisotropic giant magnetostriction, a restoration of perfect pyrochlore symmetry in low magnetic fields, and ultimately a structural phase transition in high magnetic fields. It is suggested that the magnetoelastic coupling thus revealed plays a significant role in the spin liquid physics of Tb₂Ti₂O₇ at low temperatures.