Two dimensional superconductivity in Sm2-xCexCuO4-δ: Evidence from microwave absorption

Abstract

Magnetically modulated microwave absorption (MAMMA) measurements have been performed on a superconducting Sm2-xCexCuO4-δ single crystal by sweeping the temperature at constant magnetic fields applied in different orientations. The result of each measurement is a well-defined peak, whose onset determines, in a mean field approximation, the superconducting transition. We have found that the characteristics of the MAMMA signal at any field orientation (H, θ) can be described in terms of a reduced field h = H (cos2θ + γ2sin2θ)1 2, where γ is the anisotropy parameter. The scaling of the experimental data has allowed us to determine γ ≈ 75. © 1994.