Giant magnetostriction in Ca2FeReO6 double perovskite

Abstract We report magnetostriction measurements in polycrystalline Ca 2 FeReO 6 magnetic double perovskite up to 20 T and in the temperature range 4.2–250 K. This compound shows a high Curie temperature ( T C = 523 K ) and a structural transition at low temperatures ( T S = 110 K ). By combining magnetostriction measurements parallel and perpendicular to the magnetic field, we evaluate the anisotropic ( λ t ) and volume magnetostriction ( ω ). The λ t at room temperature is large and reaches below T S the giant value of ≈0.1% at 15 T. Below T S , the ω is also found to be large: ≈0.05% at 15 T at 5 K. These results are interpreted within a scenario where the Re orbital state plays a crucial role in the ground state. The observed effect could open a new way to observe giant magnetostriction effects in transition-metal-based magnetic oxides through suitable tuning of the orbital effects in the transition metals.