Temperature and field dependence of MgB2 energy gaps from tunneling spectra

Mohamed H. Badr; K. W. Ng

doi:10.1016/S0921-4534(02)02684-9

Temperature and field dependence of MgB₂ energy gaps from tunneling spectra

Mohamed H. Badr
, K. W. Ng

Physics And Astronomy

Producción científica: Conference article › revisión exhaustiva

Resumen

We have synthesized MgB₂/Pb planar junctions to study the temperature and field dependence of the superconducting energy gap of MgB₂. The major peak occurs at Δ of about 2 meV, and this corresponds to a 2Δ/k_BT_cvalue of 1.18. While this is significantly smaller than the BCS weak coupling value, there are features in the tunneling spectra indicating the possibility of another larger gap. By fitting the dI/dV curves with a simple model, the larger gap is estimated to be about 4.5 times the smaller gap. The temperature dependence of both gaps is BCS-like, and start to open up at temperatures just below T_c (39.5 K). This confirms that these gaps are indeed bulk properties of MgB₂. The junction is stable only up to a field of 3.2 T then "collapsed" into Josephson tunneling for higher fields.

Idioma original	English
Páginas (desde-hasta)	139-140
Número de páginas	2
Publicación	Physica C: Superconductivity and its Applications
Volumen	388-389
DOI	https://doi.org/10.1016/S0921-4534(02)02684-9
Estado	Published - may 2003
Evento	proceedings of the 23rd international conference on low temper - Hiroshima, Japan Duración: ago 20 2002 → ago 27 2002

Nota bibliográfica

Funding Information:
This work was supported by NSF grant no. DMR9972071. The corresponding author would like to thank the Egyptian Ministry of Higher Education and Scientific Research for supporting this work as well.

Financiación

This work was supported by NSF grant no. DMR9972071. The corresponding author would like to thank the Egyptian Ministry of Higher Education and Scientific Research for supporting this work as well.

Financiadores	Número del financiador
National Science Foundation (NSF)
Directorate for Mathematical and Physical Sciences	9972071
Ministry of Higher Education and Scientific Research

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Condensed Matter Physics
Energy Engineering and Power Technology
Electrical and Electronic Engineering

Acceder al documento

10.1016/S0921-4534(02)02684-9

Otros archivos y enlaces

Citar esto

@article{c7b11f7d240f45adae252e3d26296159,

title = "Temperature and field dependence of MgB2 energy gaps from tunneling spectra",

abstract = "We have synthesized MgB2/Pb planar junctions to study the temperature and field dependence of the superconducting energy gap of MgB2. The major peak occurs at Δ of about 2 meV, and this corresponds to a 2Δ/kBTcvalue of 1.18. While this is significantly smaller than the BCS weak coupling value, there are features in the tunneling spectra indicating the possibility of another larger gap. By fitting the dI/dV curves with a simple model, the larger gap is estimated to be about 4.5 times the smaller gap. The temperature dependence of both gaps is BCS-like, and start to open up at temperatures just below Tc (39.5 K). This confirms that these gaps are indeed bulk properties of MgB2. The junction is stable only up to a field of 3.2 T then {"}collapsed{"} into Josephson tunneling for higher fields.",

keywords = "Energy gap, Josephson effect, MgB, Superconductivity, Tunneling",

author = "Badr, \{Mohamed H.\} and Ng, \{K. W.\}",

note = "Funding Information: This work was supported by NSF grant no. DMR9972071. The corresponding author would like to thank the Egyptian Ministry of Higher Education and Scientific Research for supporting this work as well.; proceedings of the 23rd international conference on low temper ; Conference date: 20-08-2002 Through 27-08-2002",

year = "2003",

month = may,

doi = "10.1016/S0921-4534(02)02684-9",

language = "English",

volume = "388-389",

pages = "139--140",

}

TY - JOUR

T1 - Temperature and field dependence of MgB2 energy gaps from tunneling spectra

AU - Badr, Mohamed H.

AU - Ng, K. W.

N1 - Funding Information: This work was supported by NSF grant no. DMR9972071. The corresponding author would like to thank the Egyptian Ministry of Higher Education and Scientific Research for supporting this work as well.

PY - 2003/5

Y1 - 2003/5

N2 - We have synthesized MgB2/Pb planar junctions to study the temperature and field dependence of the superconducting energy gap of MgB2. The major peak occurs at Δ of about 2 meV, and this corresponds to a 2Δ/kBTcvalue of 1.18. While this is significantly smaller than the BCS weak coupling value, there are features in the tunneling spectra indicating the possibility of another larger gap. By fitting the dI/dV curves with a simple model, the larger gap is estimated to be about 4.5 times the smaller gap. The temperature dependence of both gaps is BCS-like, and start to open up at temperatures just below Tc (39.5 K). This confirms that these gaps are indeed bulk properties of MgB2. The junction is stable only up to a field of 3.2 T then "collapsed" into Josephson tunneling for higher fields.

AB - We have synthesized MgB2/Pb planar junctions to study the temperature and field dependence of the superconducting energy gap of MgB2. The major peak occurs at Δ of about 2 meV, and this corresponds to a 2Δ/kBTcvalue of 1.18. While this is significantly smaller than the BCS weak coupling value, there are features in the tunneling spectra indicating the possibility of another larger gap. By fitting the dI/dV curves with a simple model, the larger gap is estimated to be about 4.5 times the smaller gap. The temperature dependence of both gaps is BCS-like, and start to open up at temperatures just below Tc (39.5 K). This confirms that these gaps are indeed bulk properties of MgB2. The junction is stable only up to a field of 3.2 T then "collapsed" into Josephson tunneling for higher fields.

KW - Energy gap

KW - Josephson effect

KW - MgB

KW - Superconductivity

KW - Tunneling

UR - https://www.scopus.com/pages/publications/0037850860

UR - https://www.scopus.com/pages/publications/0037850860#tab=citedBy

U2 - 10.1016/S0921-4534(02)02684-9

DO - 10.1016/S0921-4534(02)02684-9

M3 - Conference article

AN - SCOPUS:0037850860

SN - 0921-4534

VL - 388-389

SP - 139

EP - 140

JO - Physica C: Superconductivity and its Applications

JF - Physica C: Superconductivity and its Applications

T2 - proceedings of the 23rd international conference on low temper

Y2 - 20 August 2002 through 27 August 2002

ER -