Two-gap features in the specific heat of (M,K)Fe2As2(M

Abstract

The specific heat coefficient /

Electronic specific heat of Ba1−xKxFe2AsStorey1, Loram2, Cooper3 et al. 2013Phys. Rev. B468541View full textAdd to dashboardCite

“…4 and 12 we have extended the widely used [56][57][58][59] two-band α model 60 to estimate the T = 0 gaps and DOS for the three bands. In the α model the ratio α = 0 /k B T c of each gap is an adjustable parameter, and (t) = 0 δ BCS (t) where δ BCS (t) is the normalized BCS gap at t = T /T c .…”

Density functional analysis of key energetics in metal homoepitaxy: Quantum size effects in periodic slab calculations

“…Second, examination of the calculated electronic energy levels within unrelaxed clean slabs shows that one QSW ͑at k x = k y =0͒ crosses the Fermi level between L = 4 and L = 5, and another one crosses the Fermi level just below L = 10, consistent with results by Wei and Chou. 45 A simple perspective of Schulte's analyses of QSE using a jellium model 46 is that such a crossing of the Fermi energy and a QWS results in a cusp in many physical quantities if the height of the film can be adjusted continuously. A freeelectron analysis indicates that such crossing occurs approximately every five layers for Ag͑100͒ and Cu͑100͒ assuming one valence electron for each atom.…”

Quantum size effect driven thermal decomposition of Ag films on Fe(100) in the presence of pinhole-growth morphological defects

“…The negative curvature of the energy landscape between QW-induced energy local minima results in a reduction in the system energy for the bifurcation mode of decomposition. 6,16 Investigations of Ag films that were grown at room temperature confirmed the stability of 2 and 5 ML films and instability of 3 and 4 ML films during annealing. 10 However, 3 and 4 ML films were observed to decompose to stable 2 and 5 ML components, instead of their respective bifurcation morphologies.…”

“…12,13,15 Ag films on the Fe͑100͒ surface have received attention because of the impact of QW states on film energetics, morphology, and thermal stability. 6,10,16 The small lattice mismatch ͑0.7%͒ between a Ag film and the Fe͑100͒ substrate results in a system that is almost strain free. This means that stress-induced effects in film morphology 17 should not come into play and we may therefore concentrate on electronic effects.…”