Pressure dependence of Tc in L2−xMxCuO4−y (L=Pr,Nd,Sm,Eu; M=Ce,Th): Antisymmetric behavior of electron- versus hole-doped copper-oxide superconductors

Abstract

Measurements of the superconducting transition temperature ${\mathrm{T}}_{\mathrm{c}}$ in the electron-doped copper-oxide compounds ${\mathrm{L}}_{2\mathrm{-}\mathrm{x}}$ ${\mathrm{M}}_{\mathrm{x}}$ ${\mathrm{CuO}}_{4\mathrm{-}\mathrm{y}}$ under pressure P to ∼20 kbar reveal that, in general, ${\mathrm{T}}_{\mathrm{c}}$ decreases with P, in contrast to the behavior of hole-doped copper-oxide compounds. The quantity d ln${\mathrm{T}}_{\mathrm{c}}$/d lnV exhibits a dependence on ${\mathrm{T}}_{\mathrm{c}}$ similar to that of hole-doped compounds, but opposite in sign, and can be as large as ∼24. Correlation of structural and transport properties indicates competition between interlayer and intralayer effects in these materials.