Field-induced structural changes in Ca3Ru2O7

We report X-ray scattering studies of the c-axis lattice parameter in Ca3Ru2O7 as a function of temperature and magnetic field, for B 11 the ground state easy (b) axis. The step-like, similar to 0.1% change coincides in zero field with a spin reorientation and a metal-insulator transition, at Tm-i approximate to 48 K, and shifts to a lower temperature upon application of magnetic field. At temperatures well below Tm-i, negligible change in the c-axis lattice parameter is observed at the metamagnetic transition to the spin-polarized phase, at Bc approximate to 6T, which indicates that this transition does not couple to the lattice degree of freedom. (C) 2007 Elsevier B.V. All rights reserved.