Résumé
We propose to characterize “in-situ” the large strain produced under an applied magnetic field by high-resolution synchrotron x-ray diffraction in Tb0.3Dy0.7Fe2 alloy as a function of the temperature. Our preliminary results already showed a spectacular magnetic field induced phase transition. High resolution will permit to determine the structural origin of the magnetostriction in this material in the temperature magnetic field space.