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Title: Cold SQUIDs and hot samples

Abstract

Low transition temperature (low-{Tc}) and high-{Tc} Superconducting QUantum Interference Devices (SQUIDs) have been used to perform high-resolution magnetic measurements on samples whose temperatures are much higher than the operating temperatures of the devices. Part 1 of this work focuses on measurements of the rigidity of flux vortices in high-{Tc} superconductors using two low-{Tc} SQUIDs, one on either side of a thermally-insulated sample. The correlation between the signals of the SQUIDs is a direct measure of the extent of correlation between the movements of opposite ends of vortices. These measurements were conducted under the previously-unexplored experimental conditions of nominally-zero applied magnetic field, such that vortex-vortex interactions were unimportant, and with zero external current. At specific temperatures, the authors observed highly-correlated noise sources, suggesting that the vortices moved as rigid rods. At other temperatures, the noise was mostly uncorrelated, suggesting that the relevant vortices were pinned at more than one point along their length. Part 2 describes the design, construction, performance, and applications of a scanning high-{Tc} SQUID microscope optimized for imaging room-temperature objects with very high spatial resolution and magnetic source sensitivity.

Authors:
 [1]
  1. Univ. of California, Berkeley, CA (United States). Dept. of Physics
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Energy Research, Washington, DC (United States)
OSTI Identifier:
527531
Report Number(s):
LBNL-40405
ON: DE97008857; TRN: 97:016684
DOE Contract Number:  
AC03-76SF00098
Resource Type:
Technical Report
Resource Relation:
Other Information: TH: Thesis (Ph.D.); PBD: May 1997
Country of Publication:
United States
Language:
English
Subject:
66 PHYSICS; 36 MATERIALS SCIENCE; SQUID DEVICES; MAGNETIC FLUX; HIGH-TC SUPERCONDUCTORS; DESIGN; PERFORMANCE; USES; EXPERIMENTAL DATA

Citation Formats

Lee, T S.C., and Lawrence Berkeley national Lab., CA. Cold SQUIDs and hot samples. United States: N. p., 1997. Web. doi:10.2172/527531.
Lee, T S.C., & Lawrence Berkeley national Lab., CA. Cold SQUIDs and hot samples. United States. https://doi.org/10.2172/527531
Lee, T S.C., and Lawrence Berkeley national Lab., CA. 1997. "Cold SQUIDs and hot samples". United States. https://doi.org/10.2172/527531. https://www.osti.gov/servlets/purl/527531.
@article{osti_527531,
title = {Cold SQUIDs and hot samples},
author = {Lee, T S.C. and Lawrence Berkeley national Lab., CA},
abstractNote = {Low transition temperature (low-{Tc}) and high-{Tc} Superconducting QUantum Interference Devices (SQUIDs) have been used to perform high-resolution magnetic measurements on samples whose temperatures are much higher than the operating temperatures of the devices. Part 1 of this work focuses on measurements of the rigidity of flux vortices in high-{Tc} superconductors using two low-{Tc} SQUIDs, one on either side of a thermally-insulated sample. The correlation between the signals of the SQUIDs is a direct measure of the extent of correlation between the movements of opposite ends of vortices. These measurements were conducted under the previously-unexplored experimental conditions of nominally-zero applied magnetic field, such that vortex-vortex interactions were unimportant, and with zero external current. At specific temperatures, the authors observed highly-correlated noise sources, suggesting that the vortices moved as rigid rods. At other temperatures, the noise was mostly uncorrelated, suggesting that the relevant vortices were pinned at more than one point along their length. Part 2 describes the design, construction, performance, and applications of a scanning high-{Tc} SQUID microscope optimized for imaging room-temperature objects with very high spatial resolution and magnetic source sensitivity.},
doi = {10.2172/527531},
url = {https://www.osti.gov/biblio/527531}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu May 01 00:00:00 EDT 1997},
month = {Thu May 01 00:00:00 EDT 1997}
}