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.
Vortex state microwave resistivity in Tl-2212 thin films / N., Pompeo; R., Marcon; Sarti, Stefano; H., Schneidewind; E., Silva. - In: JOURNAL OF SUPERCONDUCTIVITY AND NOVEL MAGNETISM. - ISSN 1557-1939. - STAMPA. - 20:1(2007), pp. 43-49. (Intervento presentato al convegno 9th Symposium on High Temperature Superconductors in High Frequency Fields tenutosi a Cardiff, WALES nel JUN 25-28, 2006) [10.1007/s10948-006-0187-2].
Vortex state microwave resistivity in Tl-2212 thin films
SARTI, Stefano;
2007
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.
