Search for new superconductors in the La-Si-C system

ORAL

Abstract

We have searched for the presence of superconductivity in the La-Si-C system in bulk and thin film samples. This system has some of the common features that are present in high T$_{C}$ superconducting materials. It is a multi-element compound and also incorporates a light element, Carbon. Furthermore, one of the binary phases, La$_{5}$Si$_{3}$ exhibits a tetragonal layered structure. This system exhibits the presence of a possible new superconducting compound with T$_{C}$'s ranging from 6.1 K to 8.5 K. In the binary La-Si system there are five inter-metallic phases. Among these phases, those that exhibit superconductivity are: LaSi$_{2}$ with T$_{C}$ of 2.3 K, La$_{3}$Si$_{2}$ with a T$_{C}$ of 2.1 K and La$_{5}$Si$_{3}$ with a T$_{C}$ of 1.6 K. A careful analysis of several physical properties (SQUID, Modulated Microwave Absorption) and x-ray powder diffraction, (using Rietveld refinement) shows that superconductivity in this system could be ascribed to intermediate binary (La$_{2}$C$_{3})$ and single (La-\textit{$\beta $}) phases of the system.

Authors

  • Jose De la Venta

    University of California, San Diego

  • Ali C. Basaran

    University of California, San Diego

  • Ted Grant

    University of California, Irvine

  • Antonio Jefferson S. Machado

    University of California, Irvine

  • Zachary Fisk

    University of California, Irvine, Department of Physics and Astromony, University of California, Irvine, Irvine, CA 92697, Department of Physics, University of California, Irvine

  • I.K. Schuller

    Department of Physics and Center for Advanced Nanotechnology, University of California San Diego, La Jolla, California 92093, University of California, San Diego, Department of Physics and Center for Advanced Nanoscience, University of California San Diego, La Jolla CA 92093, University of California-San Diego