Electron-tunneling studies on the superconducting ( La 1 − x Sr</mml:mi…
1990; American Physical Society; Volume: 42; Issue: 13 Linguagem: Inglês
10.1103/physrevb.42.8049
ISSN1095-3795
AutoresToshikazu Ekino, Jun Akimitsu,
Tópico(s)Superconductivity in MgB2 and Alloys
ResumoWe report the results of tunneling measurements on (${\mathrm{La}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Sr}}_{\mathit{x}}$${)}_{2}$${\mathrm{CuO}}_{4}$ and R${\mathrm{Ba}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{\mathit{y}}$ (R=Y,Er,Gd) at several x and y values having various ${\mathit{T}}_{\mathit{c}}$'s. The ratios 2\ensuremath{\Delta}/${\mathit{kT}}_{\mathit{c}}$ are 4.5--4.9 for (${\mathrm{La}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Sr}}_{\mathit{x}}$${)}_{2}$${\mathrm{CuO}}_{4}$ and 3.3--4.2 for R${\mathrm{Ba}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{\mathit{y}}$. The shapes of the tunneling density of states, anisotropies of the gaps, and temperature dependences of the gaps are also discussed.
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