## Abstract

We use strong coupling theory of superconductivity to perform a detailed analysis of the Eliashberg functions {alpha}{sup 2}F({omega}), for thirteen samples of Nb-Ge with critical temperatures ranging from 7.0 K to 21.1K. As critical temperature increases, we analyze the general trends of the electron-phonon coupling parameter {lambda}, of the integral of {alpha}{sup 2}F({omega})``A``, and of other characteristics of {alpha}{sup 2}F({omega}) on the basis of qualitative or empirical criteria. While we find that the samples have in general the behavior expected, a closer analysis points to an overall attenuation in {alpha}{sup 2}F({omega}) of unclear origin. Though the gap edge, {Delta}{sub 0}, appears to be well described by the {alpha}{sup 2}F({omega}) obtained, the thermodynamic critical field agrees poorly with that reproduced by {alpha}{sup 2}F({omega}) in the only case where the necessary (tunneling {alpha}{sup 2}F({omega}), critical field measurements) data are available. Our analysis suggests there is a gross uncertainty in the measured H{sub c}(0). The overall analysis shows that the samples obtained are of enough quality to already give meaningful results upon inversion of the tunneling data. (author). 23 refs, 14 figs, 6 tabs.

Baquero, R;

^{[1] }Gutierrez-Ibarra, J;^{[2] }Kihlstrom, K E^{[3] }- International Centre for Theoretical Physics, Trieste (Italy)
- Universidad Autonoma de Puebla (Mexico). Escuela de Fisica
- Westmont College, Santa Barbara, CA (USA). Dept. of Physics

## Citation Formats

Baquero, R, Gutierrez-Ibarra, J, and Kihlstrom, K E.
Eliashberg theory applied to the study of an Nb-Ge series.
IAEA: N. p.,
1991.
Web.

Baquero, R, Gutierrez-Ibarra, J, & Kihlstrom, K E.
Eliashberg theory applied to the study of an Nb-Ge series.
IAEA.

Baquero, R, Gutierrez-Ibarra, J, and Kihlstrom, K E.
1991.
"Eliashberg theory applied to the study of an Nb-Ge series."
IAEA.

@misc{etde_10105011,

title = {Eliashberg theory applied to the study of an Nb-Ge series}

author = {Baquero, R, Gutierrez-Ibarra, J, and Kihlstrom, K E}

abstractNote = {We use strong coupling theory of superconductivity to perform a detailed analysis of the Eliashberg functions {alpha}{sup 2}F({omega}), for thirteen samples of Nb-Ge with critical temperatures ranging from 7.0 K to 21.1K. As critical temperature increases, we analyze the general trends of the electron-phonon coupling parameter {lambda}, of the integral of {alpha}{sup 2}F({omega})``A``, and of other characteristics of {alpha}{sup 2}F({omega}) on the basis of qualitative or empirical criteria. While we find that the samples have in general the behavior expected, a closer analysis points to an overall attenuation in {alpha}{sup 2}F({omega}) of unclear origin. Though the gap edge, {Delta}{sub 0}, appears to be well described by the {alpha}{sup 2}F({omega}) obtained, the thermodynamic critical field agrees poorly with that reproduced by {alpha}{sup 2}F({omega}) in the only case where the necessary (tunneling {alpha}{sup 2}F({omega}), critical field measurements) data are available. Our analysis suggests there is a gross uncertainty in the measured H{sub c}(0). The overall analysis shows that the samples obtained are of enough quality to already give meaningful results upon inversion of the tunneling data. (author). 23 refs, 14 figs, 6 tabs.}

place = {IAEA}

year = {1991}

month = {Jul}

}

title = {Eliashberg theory applied to the study of an Nb-Ge series}

author = {Baquero, R, Gutierrez-Ibarra, J, and Kihlstrom, K E}

abstractNote = {We use strong coupling theory of superconductivity to perform a detailed analysis of the Eliashberg functions {alpha}{sup 2}F({omega}), for thirteen samples of Nb-Ge with critical temperatures ranging from 7.0 K to 21.1K. As critical temperature increases, we analyze the general trends of the electron-phonon coupling parameter {lambda}, of the integral of {alpha}{sup 2}F({omega})``A``, and of other characteristics of {alpha}{sup 2}F({omega}) on the basis of qualitative or empirical criteria. While we find that the samples have in general the behavior expected, a closer analysis points to an overall attenuation in {alpha}{sup 2}F({omega}) of unclear origin. Though the gap edge, {Delta}{sub 0}, appears to be well described by the {alpha}{sup 2}F({omega}) obtained, the thermodynamic critical field agrees poorly with that reproduced by {alpha}{sup 2}F({omega}) in the only case where the necessary (tunneling {alpha}{sup 2}F({omega}), critical field measurements) data are available. Our analysis suggests there is a gross uncertainty in the measured H{sub c}(0). The overall analysis shows that the samples obtained are of enough quality to already give meaningful results upon inversion of the tunneling data. (author). 23 refs, 14 figs, 6 tabs.}

place = {IAEA}

year = {1991}

month = {Jul}

}