It was recalled that the heat instability which was introduced by linear defects was assumed to enhance the marked difference between the microwave properties of single crystals and thin films, in this material, due to extended strain fields near to out-of-plane edge dislocations. It was shown theoretically, and confirmed experimentally, that a single dislocation could not have a strong effect upon the surface resistance, but that dislocation arrays (which were observed experimentally) could introduce thermal instability if edge dislocations in the arrays were spaced closer than the heat relaxation length. Ordered dislocation structures provided a much higher local temperature perturbation than did randomly distributed dislocations.

Defect-Induced Thermal Instability in YBCO Films in Microwave Field. V.M.Pan, C.G.Tretiatchenko, V.S.Flis, V.A.Komashko, E.A.Pashitskii, A.N.Ivanyuta, G.A.Melkov, H.Zandbergen, V.L.Svetchnikov: Physica C, 2003, 388-389, 471-2