Activation energy in La0.7Ca0.3MnO3/YBa2Cu3O7-δ / La0.7Ca0.3MnO3 superconducting trilayers M. Salvato, F. Bobba, G. Calabrese, C. Cirillo, A. M. Cucolo, A. De Santis, A. Vecchione and C. Attanasio Eur. Phys. J. B, 51 1 (2006) 79-85 Published online: 31 May 2006 DOI: 10.1140/epjb/e2006-00200-4