We present measurements of the field induced changes in the 47 GHz complex resistivity, Delta(rho) over bar (H, T), in Tl2Ba2CaCu2O8+x (TBCCO) thin films with T (c) similar or equal to 105 K, prepared on CeO2 buffered sapphire substrates. At low fields (mu(0) H < 10 mT) a very small irreversible feature is present, suggesting a little role of intergranular phenomena. Above that level Delta(rho) over bar (H, T) exhibits a superlinear dependence with the field, as opposed to the expected (at high frequencies) quasilinear behaviour. We observe a crossover between predominantly imaginary to predominantly real (dissipative) response with increasing temperature and/or field. In addition, we find the clear scaling property Delta(rho) over bar (H, T) = Delta(rho) over bar [H/H * (T)], where the scaling field H * (T) maps closely the melting field measured in single crystals. We discuss our microwave results in terms of loss of flux lines rigidity.
Pompeo, N., Sarti, S., Marcon, R., Schneidewind, H., Silva, E. (2007). Vortex state microwave resistivity in Tl-2212 thin films. JOURNAL OF SUPERCONDUCTIVITY AND NOVEL MAGNETISM, 20(1), 43-49 [10.1007/s10948-006-0187-2].
Vortex state microwave resistivity in Tl-2212 thin films
POMPEO, NICOLA;SILVA, Enrico
2007-01-01
Abstract
We present measurements of the field induced changes in the 47 GHz complex resistivity, Delta(rho) over bar (H, T), in Tl2Ba2CaCu2O8+x (TBCCO) thin films with T (c) similar or equal to 105 K, prepared on CeO2 buffered sapphire substrates. At low fields (mu(0) H < 10 mT) a very small irreversible feature is present, suggesting a little role of intergranular phenomena. Above that level Delta(rho) over bar (H, T) exhibits a superlinear dependence with the field, as opposed to the expected (at high frequencies) quasilinear behaviour. We observe a crossover between predominantly imaginary to predominantly real (dissipative) response with increasing temperature and/or field. In addition, we find the clear scaling property Delta(rho) over bar (H, T) = Delta(rho) over bar [H/H * (T)], where the scaling field H * (T) maps closely the melting field measured in single crystals. We discuss our microwave results in terms of loss of flux lines rigidity.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.