We performed point-contact spectroscopy (PCS) measurements in Mg1−xMnxB2 single crystals, with x ≤ 0.015 and bulk Tc down to 13.3 K. The gaps σ and π were obtained by fitting the conductance curves of the point contacts with the two-band Blonder–Tinkham– Klapwijk (BTK) model. Both σ and π decrease with the critical temperature of the junctions TAc , but remain clearly distinct down to the lowest critical temperature (TAc∼=9 K). Once analyzed within the Eliashberg theory, the gap trends as a function of TAc can be explained by a doping-induced increase in the pair-breaking scattering within the σ band, with smaller contributions from the π-π or the σ-π channels.

Point-Contact Spectroscopy in Mn-Doped MgB2 Single Crystals: Effects of Magnetic Impurities in a Two-Band Superconductor / Daghero, Dario; Calzolari, Andrea; Tortello, Mauro; Ummarino, Giovanni; Gonnelli, Renato; Stepanov, V. A; Zhigadlo, N; Rogacki, K; Karpinski, J.. - In: JOURNAL OF SUPERCONDUCTIVITY AND NOVEL MAGNETISM. - ISSN 1557-1939. - STAMPA. - 20:7-8(2007), pp. 523-526. [10.1007/s10948-007-0281-0]

Point-Contact Spectroscopy in Mn-Doped MgB2 Single Crystals: Effects of Magnetic Impurities in a Two-Band Superconductor

DAGHERO, Dario;CALZOLARI, ANDREA;TORTELLO, MAURO;UMMARINO, Giovanni;GONNELLI, Renato;
2007

Abstract

We performed point-contact spectroscopy (PCS) measurements in Mg1−xMnxB2 single crystals, with x ≤ 0.015 and bulk Tc down to 13.3 K. The gaps σ and π were obtained by fitting the conductance curves of the point contacts with the two-band Blonder–Tinkham– Klapwijk (BTK) model. Both σ and π decrease with the critical temperature of the junctions TAc , but remain clearly distinct down to the lowest critical temperature (TAc∼=9 K). Once analyzed within the Eliashberg theory, the gap trends as a function of TAc can be explained by a doping-induced increase in the pair-breaking scattering within the σ band, with smaller contributions from the π-π or the σ-π channels.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11583/2502550
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