Systematics in the superconducting and normal state properties in chemically substituted MgB$_{2}$

dc.creatorBalaselvi, S. Jemima
dc.creatorBharathi, A.
dc.creatorSastry, V. Sankara
dc.creatorReddy, G. L. N.
dc.creatorHariharan, Y.
dc.date2003-03-03
dc.date.accessioned2026-07-07T02:49:58Z
dc.date.available2026-07-07T02:49:58Z
dc.descriptionThe superconducting transition temperature, T$_{C}$, the residual resistivity $ρ_{0}$ and the slope of resistivity curve at high temperature, d$ρ$/dT, have been measured in a series of MgB$_{2}$ samples that have been chemically substituted to varying degree with Li or Cu at the Mg-site and by Li or Cu at the Mg-site along with C substitution at the B-site. DC resistivity and ac susceptibility measurements were employed to extract the above parameters. T$_{C}$ versus the electron count (estimated from simple chemical valence count arguments) shows a universal behaviour, with T$_{C}$ being constant at the MgB$_{2}$ value for electron counts lower than in MgB$_{2}$ but rapidly decreasing for larger electron counts. The temperature dependence of resistivity in the normal state fits to the Bloch- Gruneisen formula, from which the Debye temperature, $θ_{D}$, and the $ρ_{0}$ are extracted. $θ_{D}$ variation with T$_{C}$ is not systematic, whereas $ρ_{0}$ versus T$_{C}$ shows a systematic variation that depends on the type of the chemical substituent. This dependence has a signature of the nature of the intraband/interband scattering affected by the chemical substitutions. d$ρ$/dT increases with C substitution, but decreases with Li and Cu substitution, implying that C substitution leads to the domination of conductivity by the $σ$ band, while in the Li/Cu substituted samples the $π$ band dominates conduction.
dc.descriptionSubmitted to Phys. Rev B on 24th Feb 2003
dc.identifierhttps://arxiv.org/abs/cond-mat/0303022
dc.identifierhttp://arxiv.org/abs/cond-mat/0303022
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/20963
dc.subjectSuperconductivity
dc.titleSystematics in the superconducting and normal state properties in chemically substituted MgB$_{2}$
dc.typetext

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