Low-temperature specific heat of polycrystallineBa0.6K0.4

Theory of a higher-order phase transition: The superconducting transition inBa0.6K0.4BiOKumar1 2003Phys. Rev. B100120View full textAdd to dashboardCite

“…But they also noted that "if it is a bulk effect, then we may have to invoke a new, as yet unidentified, mechanism for its cause". Soon after the discovery of superconductivity in BKBO by Cava et al 6 , the early specific heat measurements 25,26 were already reporting the missing specific heat anomaly. There was one report 27 of a small specific heat discontinuity but the two other measurements were unable to verify it.…”

“…On the other side of this story, there is an estimate which yields an expected ∆C at least three orders of magnitude larger. According to Hundley et al 25,26 , the normal state specific heat in BKBO can be fit to an electronic contribution of C/T = γ = 0.15 J/mole K 2 . The data, when plotted as C/T vs.T 2 , show two straight lines with a crossover around 16K.…”

Magnetization measurements on single crystals of superconducting Ba 0.6 K 0.4 BiO 3

“…Therefore, the broadening of the transition may be due to effects other than fluctuations. Several studies of the specific heat of BKBO have been done (Hundley, Thompson, and Kwei, 1989;Graebner, Scheenmeyer, and Thomas, 1989;Stupp, Reeves, Ginsberg, Hinks, Dabrowski, and Vandervoort, 1989;Alba, 1992). All but one study (Graebner et al, 1989)) conclude that ∆C p is zero across the transition.…”

Superconducting-Normal Phase Transition in(Ba1−xKx)Woodfield1, Wright2, Fisher3 et al. 1999Phys. Rev. Lett.220160View full textAdd to dashboardCite

“…It is ϳ4 times greater than that obtained in the measurements reported here, 0.27 mJ K 24 mol 21 for x 0.40. In addition, although there are three other reported values of B 3 in the range 0.23-0.38 mJ K 24 mol 21 [8][9][10], there are none near 1.05 mJ K 24 mol 21 .…”