TY - JOUR
T1 - Effects of self field and low magnetic fields on the normal-superconducting phase transition
AU - Sullivan, M. C.
AU - Strachan, D. R.
AU - Frederiksen, T.
AU - Ott, R. A.
AU - Lobb, C. J.
PY - 2005/9/1
Y1 - 2005/9/1
N2 - Researchers have studied the normal-superconducting phase transition in the high-Tc cuprates in a magnetic field (the vortex-glass or Bose-glass transition) and in zero field. Often, transport measurements in "zero field" are taken in the Earth's ambient field or in the remnant field of a magnet. We show that fields as small as the Earth's field will alter the shape of the current vs voltage curves and will result in inaccurate values for the critical temperature Tc and the critical exponents ν and z, and can even destroy the phase transition. This indicates that without proper screening of the magnetic field it is impossible to determine the true zero-field critical parameters, making correct scaling and other data analysis impossible. We also show, theoretically and experimentally, that the self field generated by the current flowing in the sample has no effect on the current vs voltage isotherms.
AB - Researchers have studied the normal-superconducting phase transition in the high-Tc cuprates in a magnetic field (the vortex-glass or Bose-glass transition) and in zero field. Often, transport measurements in "zero field" are taken in the Earth's ambient field or in the remnant field of a magnet. We show that fields as small as the Earth's field will alter the shape of the current vs voltage curves and will result in inaccurate values for the critical temperature Tc and the critical exponents ν and z, and can even destroy the phase transition. This indicates that without proper screening of the magnetic field it is impossible to determine the true zero-field critical parameters, making correct scaling and other data analysis impossible. We also show, theoretically and experimentally, that the self field generated by the current flowing in the sample has no effect on the current vs voltage isotherms.
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U2 - 10.1103/PhysRevB.72.092507
DO - 10.1103/PhysRevB.72.092507
M3 - Article
AN - SCOPUS:29744444898
SN - 1098-0121
VL - 72
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 9
M1 - 092507
ER -