The experimental determination of the scaling of the superconducting critical temperature ( T c ) vs the Fermi temperature ( T f ) of the holes in the boron σ subband is presented. The Fermi level has been tuned near the “shape resonance,” i.e., the two- to three-dimensional crossover of the Fermi surface of the boron σ subband by changing the Al/Mg content in Al 1 - x Mg x B 2 . The product k f ξ 0 of the Fermi wave vector ( k f ) times the superconducting Pippard coherence length ( ξ 0 ), that is a measure of the pairing strength, remains constant, kF ξ0 = 90 for x >0.66. This high-Tc phase occurs in the boron superlattice under a tensile microstrain in the range 3%< ɛ <6%.

The scaling of the critical temperature with the Fermi temperature in diborides / Bianconi, Antonio; S., Agrestini; Di Castro, Daniele; Campi, Gaetano; G., Zangari; Saini, Naurang Lal; A., Saccone; S., De Negri; M., Giovannini; G., Profeta; A., Continenza; G., Satta; S., Massidda; A. Cassetta A., Pifferi; Colapietro, Marcello. - In: PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS. - ISSN 1098-0121. - STAMPA. - 65:(2002), pp. 174515-1-174515-5. [10.1103/PhysRevB.65.174515]

The scaling of the critical temperature with the Fermi temperature in diborides

BIANCONI, Antonio;DI CASTRO, Daniele;CAMPI, GAETANO;SAINI, Naurang Lal;COLAPIETRO, Marcello
2002

Abstract

The experimental determination of the scaling of the superconducting critical temperature ( T c ) vs the Fermi temperature ( T f ) of the holes in the boron σ subband is presented. The Fermi level has been tuned near the “shape resonance,” i.e., the two- to three-dimensional crossover of the Fermi surface of the boron σ subband by changing the Al/Mg content in Al 1 - x Mg x B 2 . The product k f ξ 0 of the Fermi wave vector ( k f ) times the superconducting Pippard coherence length ( ξ 0 ), that is a measure of the pairing strength, remains constant, kF ξ0 = 90 for x >0.66. This high-Tc phase occurs in the boron superlattice under a tensile microstrain in the range 3%< ɛ <6%.
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11573/130338
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