Anisotropic resistivity of single-crystal Sm2−xCexCuO4−y

The anisotropic resistivity of electron-doped superconducting Sm2−xCexCuO4−y single crystals was measured for the first time using the Montgomery method. The data revealed very large resistive anisotropies, ϱc/ϱa≈15,000–30,000. Such anisotropy is comparable to that of the Nd2−xCexCuO4−y system (ϱc/ϱa≈5,000–20,000) and the Bi2Sr2CaCu2O8−x system. Also, the in-plane resistivity values observed here are roughly a factor of 10 lower than recently reported from measurements using other lead configurations. The T-dependent part of in-plane resistivity is nearly T2, which the out-of-plane component is nearly T2, while the out-of-plane component is nearly T32 between 80 and 300 after the subtraction of low temperature behavior proportional to -logT. Crystals exhibit interesting non-monotonic resistive anisotropy as a function of temperature, both in the transition region and in the normal state.