Measurement of the superconducting energy gap in La-Ba-Cu oxide and La-Sr-Cu oxide
Stephen E. Russek, P. E. Sulewski, A.J. Sievers, H. D. Hallen, D. K. Lathrop, R A. Buhrman
We report on far-infared (FIR) reflectivity measurements on sintered pressed poweder samples of La-Ba-Cu oxide and La-Sr-Cu oxide. THe best samples show fairly sharp transitions to zero measurable resistance with a transition midpoint of 28 K for the Ba alloy and 36 K for the Sr alloy. The FIR measurements reveal an energy gap below Tc with, depending on the measurement criterion used, values of 2delta/kbTc of 1.3-1.95 for La-Ba-Cu oxide and 1.6-2.7 for La-Sr-Cu oxide, which are lower than expected for a BCS superconductor.
, Sulewski, P.
, Sievers, A.
, Hallen, H.
, Lathrop, D.
and Buhrman, R.
Measurement of the superconducting energy gap in La-Ba-Cu oxide and La-Sr-Cu oxide, Physical Review B, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=905792
(Accessed November 26, 2022)