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Title: Observations of YBCO superconductors under a low-temperature scanning electron microscope

Abstract

Microscopic analyses have been performed on YBCO superconductors with Ca-doping and Gd-doping as a function of temperature by employing a low-temperature scanning electron microscope (LTSEM). On lowering temperature of the sample from 300 K to 90 K, the brightness of the SEM image changes due to the change in resistance of the sample. For the underdoped cuprates Y{sub 1-x}Ca{sub x}Ba{sub 2}Cu{sub 3}O{sub 7-{delta}}, with x=0.2, the pseudo gap in the normal state is opened at a temperature T* which far below the critical temperature T{sub c} of the superconductor. The opening of the pseudo gap has directly been observed under LTSEM (temperature fluctuating in the range of {+-}5 K). At temperature T* the formation of quasi-particles takes place, thus a sudden brightness change in the SEM image is observed. The results of these measurements are compared with the four-point probe measurements. It is proved that the data of these two measurements are quite in agreement with each other.

Authors:
; ; ;  [1];  [2]
  1. Department of Physics and Materials Science, City University of Hong Kong, Hong Kong (China)
  2. Department of Physics, University of Hong Kong, Hong Kong (China)
Publication Date:
OSTI Identifier:
21208282
Resource Type:
Journal Article
Journal Name:
AIP Conference Proceedings
Additional Journal Information:
Journal Volume: 483; Journal Issue: 1; Conference: 1999 University of Miami conference on high temperature superconductivity, Coral Gables, FL (United States), 7-13 Jan 1999; Other Information: DOI: 10.1063/1.59652; (c) 1999 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0094-243X
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; BARIUM OXIDES; COPPER OXIDES; CRITICAL TEMPERATURE; CUPRATES; DOPED MATERIALS; ENERGY GAP; HIGH-TC SUPERCONDUCTORS; QUASI PARTICLES; SCANNING ELECTRON MICROSCOPY; TEMPERATURE DEPENDENCE; YTTRIUM OXIDES

Citation Formats

Vyas, A., Lam, C. C., Li, S. H., Lam, H. S., and Fung, P. C. W. Observations of YBCO superconductors under a low-temperature scanning electron microscope. United States: N. p., 1999. Web. doi:10.1063/1.59652.
Vyas, A., Lam, C. C., Li, S. H., Lam, H. S., & Fung, P. C. W. Observations of YBCO superconductors under a low-temperature scanning electron microscope. United States. doi:10.1063/1.59652.
Vyas, A., Lam, C. C., Li, S. H., Lam, H. S., and Fung, P. C. W. Wed . "Observations of YBCO superconductors under a low-temperature scanning electron microscope". United States. doi:10.1063/1.59652.
@article{osti_21208282,
title = {Observations of YBCO superconductors under a low-temperature scanning electron microscope},
author = {Vyas, A. and Lam, C. C. and Li, S. H. and Lam, H. S. and Fung, P. C. W.},
abstractNote = {Microscopic analyses have been performed on YBCO superconductors with Ca-doping and Gd-doping as a function of temperature by employing a low-temperature scanning electron microscope (LTSEM). On lowering temperature of the sample from 300 K to 90 K, the brightness of the SEM image changes due to the change in resistance of the sample. For the underdoped cuprates Y{sub 1-x}Ca{sub x}Ba{sub 2}Cu{sub 3}O{sub 7-{delta}}, with x=0.2, the pseudo gap in the normal state is opened at a temperature T* which far below the critical temperature T{sub c} of the superconductor. The opening of the pseudo gap has directly been observed under LTSEM (temperature fluctuating in the range of {+-}5 K). At temperature T* the formation of quasi-particles takes place, thus a sudden brightness change in the SEM image is observed. The results of these measurements are compared with the four-point probe measurements. It is proved that the data of these two measurements are quite in agreement with each other.},
doi = {10.1063/1.59652},
journal = {AIP Conference Proceedings},
issn = {0094-243X},
number = 1,
volume = 483,
place = {United States},
year = {1999},
month = {9}
}