Comparison of various methods to determine experimentally the irreversibility line in superconductors

S. Ramakrishnan; Ravi Kumar; P. L. Paulose; A. K. Grover; P. Chaddah

doi:10.1103/PhysRevB.44.9514

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Comparison of various methods to determine experimentally the irreversibility line in superconductors

S. Ramakrishnan, Ravi Kumar, P. L. Paulose, A. K. Grover, P. Chaddah

DOI 10.1103/PhysRevB.44.9514 · Physical Review B

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Abstract

An attempt has been made to determine the irreversibility temperatures [Tr(H)] via the merger of zero-field-cooled and field-cooled magnetizations, via the vanishing of the isothermal hysteresis, and via the appearance of the differential paramagnetic effect in specimens of lead and niobium. The first method appears to define a lower limit on Tr(H) and does not necessarily indicate a true thermodynamic region near Tc(H). The differential paramagnetic effect, however, is a qualitative feature whose presence is sufficient to imply reversibility.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
Pb Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown
Nb Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown
YBa2Cu3O7 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown
PbMo6S8 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown