Magnetic properties and electronic conduction of superconducting<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">La</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn><mml:mi mathvariant="normal">−</mml:mi><mml:mi mathvariant="italic">x</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Sr</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="italic">x</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">CuO</mml:mi></mml:mrow><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>

Magnetic susceptibility \ensuremath{\chi} and resistivity were measured in ${\mathrm{La}}_{2\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Sr}}_{\mathit{x}}$${\mathrm{CuO}}_{4}$. Enhancement of \ensuremath{\chi} due to a ferromagnetic correlation, which is inherent in the orthorhombic phase at low Sr concentrations, disappears at around x=0.05, near the margin of the superconducting regime. In superconducting samples with 0.1\ensuremath{\lesssim}x\ensuremath{\lesssim}0.2, \ensuremath{\chi} exhibits a broad peak at a temperature ${\mathit{T}}_{\mathrm{max}}$. The T-dependent part of \ensuremath{\chi}, ${\mathrm{\ensuremath{\chi}}}^{\mathit{s}}$(T), follows a single curve F regardless of x when ${\mathrm{\ensuremath{\chi}}}^{\mathit{s}}$ and T are normalized with the peak value ${\mathrm{\ensuremath{\chi}}}_{\mathrm{max}}^{\mathit{s}}$ and ${\mathit{T}}_{\mathrm{max}}$, as has been reported. However, the present scaling curve F decreases much more at T\ensuremath{\ll}${\mathit{T}}_{\mathrm{max}}$ than the reported one. The resistivity exhibits a T-linear dependence above a temperature ${\mathit{T}}^{\mathrm{*}}$ and deviates downward from the T-linear dependence below ${\mathit{T}}^{\mathrm{*}}$. For x&gt;0.1 the temperature ${\mathit{T}}^{\mathrm{*}}$ agrees well with ${\mathit{T}}_{\mathrm{max}}$, indicating that the deviation from a T-linear resistivity is related to the decrease of \ensuremath{\chi} below ${\mathit{T}}_{\mathrm{max}}$. On the other hand, for x0.1 a large reduction of \ensuremath{\chi} is seen below \ensuremath{\sim}${\mathit{T}}^{\mathrm{*}}$ in the data up to 1000 K by Yoshizaki et al., although no peak is seen in the \ensuremath{\chi}-T curve. The T dependence of \ensuremath{\chi} in ${\mathrm{La}}_{2\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Sr}}_{\mathit{x}}$${\mathrm{Cu}}_{1\mathrm{\ensuremath{-}}\mathit{y}}$${\mathrm{Zn}}_{\mathit{y}}$${\mathrm{O}}_{4}$ is also reported for x=0.16 and 0.22.

Перевод пока недоступен