Anisotropy and reversible magnetization of the infinite-layer superconductorSr0.9La0.1CuO2

Abstract

We present reversible magnetization measurements of a c-axis aligned ${\mathrm{Sr}}_{0.9}{\mathrm{La}}_{0.1}{\mathrm{CuO}}_{2}$ infinite-layer superconductor with ${T}_{c}\ensuremath{\simeq}43\mathrm{K}.$ The magnetization measured as a function of temperature and angle between the c axis and the external magnetic field are analyzed in terms of the Hao-Clem model. Consequently, the critical fields $[{H}_{c}(0),$ ${H}_{c1}^{c}(0),$ and ${H}_{c2}^{c}(0)]$ and the characteristic lengths $[{\ensuremath{\xi}}_{\mathrm{ab}}(0)$ and ${\ensuremath{\lambda}}_{\mathrm{ab}}(0)]$ are derived. We introduce a novel technique to describe the angular dependence of magnetization using the Hao-Clem model by employing the effective mass anisotropy. The anisotropy ratio $\ensuremath{\gamma}=9.3$ and the zero-temperature coherence length along the c axis ${\ensuremath{\xi}}_{c}(0)=5.2\AA{}$ are obtained by the technique. The coherence length ${\ensuremath{\xi}}_{c}(0)$ is longer than the c-axis lattice parameter $c=3.41\AA{},$ which implies three-dimensional coupling between ${\mathrm{CuO}}_{2}$ planes even at zero temperature.