The C-axis Magnetoresistivity Of Sr₂RuO₄

The study of the nonconventional superconductivity is one of the most interesting and important topics in Condensed Matter Physics in resent years. As a first noncuprate oxide superconductivity, Sr2RuO4 has attracted so many interests since its discovery. A serial experiments and theories have proved that the normal state of Sr2RuO4 is 2D Fermi Liquid behavior and the superconducting state is unconventional spin-triplet p-wave paired superconductor.It is reported that the magnetoresistance (MR) measurement is a useful tool since it is more sensitive to the change in the charge carrier scattering ratel/r, effective mass m, and the geometry of the Fermi surface. The superconducting fluctuation analysis is refer to the thermodynamic behavior near superconducting phase transitions, from which the important information about superconducting can be obtained.Using PPMS we measured the c-axis resistance and magnetoresistance near superconducting transition temperature in Sr2RuO4.The result shows that when temperature is increased the resistance behaves from a good metal across a maxim at 130K then to a semiconductor. And the low temperature behavior (T<15K) follows the Fermi-Liquid behavior.In normal state by analyze the magnetoresistance we have obtained the in-plane mean free path l//. When the results of 4K and 6K was plotted in p/p-(H/p)2 figure both of the curves can be fall down onto one linear line, which indicate that the magnetoresistance is mostly come from the orbital contribution.A large positive magnetoresistance near Tc has been observed and which is originated from superconducting fluctuations. The fluctuation-enhanced magneto-conductivity very close to Tc show well agreement with Aslamasov- Larkin(AL) prediction for a 2D superconductor, and the coherence lengths of Sr2RuCO4, ab(0) and c(0) have been deduced from fluctuation magnetoresistance analysis at 1.5K. Finally, a simple power law magnetic field dependent scaling rule was proposed for magnetoresistance at temperatures below and above Tc.