The microwave properties of polycrystalline MgB2 thin films prepared by the so-called in situ method are investigated. The characterization of the films at microwave frequencies was obtained by a coplanar resonator technique. The analysis of the experimental data results in the determination of penetration depth, surface impedance, and complex conductivity. The aim of this work is to set the experimental results in a consistent framework, involving the two-band model in the presence of impurity scattering. The energy gaps are calculated and the contribution of intra- and interband scattering is considered. From the comparison between the calculated gap values and the experimental data it turns out that the temperature dependence of the penetration depth can be accounted for by an effective mean energy gap, in agreement with the predictions of V. G. Kogan and N. V. Zhelezina Phys. Rev. B 69, 132506 2004. On the other hand, the temperature dependence of the real part of the microwave conductivity and of the surface resistance is accounted for by the single smaller gap, in agreement with the work of B. B. Jin, T. Dahm, A. I. Gubin, E.-M. Choi, H. J. Kim, S.-I. Lee, W. N. Kang, and N. Klein Phys. Rev. Lett. 91, 127006 2003. Since these findings rely on the same calculated gap structure, the required consistency is fulfilled.

Effective gap at microwave frequencies in MgB2 thin films with strong interband scattering / Ghigo, Gianluca; Botta, Danilo; Chiodoni, Angelica; Gozzelino, Laura; Gerbaldo, Roberto; Laviano, Francesco; Mezzetti, Enrica; E., Monticone; C., Portesi. - In: PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS. - ISSN 1098-0121. - 71:(2005), pp. 214522-1-214522-6. [10.1103/PhysRevB.71.214522]

Effective gap at microwave frequencies in MgB2 thin films with strong interband scattering

GHIGO, GIANLUCA;BOTTA, Danilo;CHIODONI, ANGELICA;GOZZELINO, LAURA;GERBALDO, Roberto;LAVIANO, FRANCESCO;MEZZETTI, Enrica;
2005

Abstract

The microwave properties of polycrystalline MgB2 thin films prepared by the so-called in situ method are investigated. The characterization of the films at microwave frequencies was obtained by a coplanar resonator technique. The analysis of the experimental data results in the determination of penetration depth, surface impedance, and complex conductivity. The aim of this work is to set the experimental results in a consistent framework, involving the two-band model in the presence of impurity scattering. The energy gaps are calculated and the contribution of intra- and interband scattering is considered. From the comparison between the calculated gap values and the experimental data it turns out that the temperature dependence of the penetration depth can be accounted for by an effective mean energy gap, in agreement with the predictions of V. G. Kogan and N. V. Zhelezina Phys. Rev. B 69, 132506 2004. On the other hand, the temperature dependence of the real part of the microwave conductivity and of the surface resistance is accounted for by the single smaller gap, in agreement with the work of B. B. Jin, T. Dahm, A. I. Gubin, E.-M. Choi, H. J. Kim, S.-I. Lee, W. N. Kang, and N. Klein Phys. Rev. Lett. 91, 127006 2003. Since these findings rely on the same calculated gap structure, the required consistency is fulfilled.
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11583/1676365
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo