NMR measurements of Al$_{20}$V$_{2}$La and Al$_{20}$V$_{2}$Eu

ORAL

Abstract

The Al$_{20}$V$_{2}$$R$ system, with $R$ = rare earth, features $R$ atoms in 16-atom Al cages. Our previous work on Al$_{20}$V$_{2}$Eu showed the development of underscreened Kondo behavior at low temperatures. From $^{27}$Al NMR measurements of nonmagnetic Al$_{20}$V$_{2}$La we identify the local electronic behavior of all three Al framework sites, and $T$$_{1}$ measurements indicate a significant difference between the behavior of two of the sites. At high temperatures, pseudogap behavior is observed, which is also supported by electronic calculations using the WIEN2k package. These calculations are also in excellent agreement with the measured specific heat. We conclude that the spin-fluctuation behavior in Al$_{20}$V$_{2}$Eu results from the rare-earth atom rather than from the Al-V framework. Transport measurements also could be fit to a Bloch-Gruneisen behavior, and by taking the difference, the magnetic contribution to the resistivity of Al$_{20}$V$_{2}$Eu could be identified, including a $T$-linear magnetoresistance which disappears at about 100 K, along with the apperance of Kondo behavior.

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Authors

  • Edward Fry

    Institute for Astronomy, ETH, National Optical Astronomy Observatory, Department of Physics, ETH, Texas A&M University, LANL, American Physical Society, Society of Physics Students National Office, Texas Tech University, University of Texas, Universite d'Orleans, Steward Observatory, University of Arizona, Texas A\&M University-Commerce, Texas A\&M University, Institute for Quantum Electronics, ETH Zurich, Department of Engineering and Applied Science, Harvard University, Rice University, University of Houston, Bucknell University, Department of Physics, Texas A\&M University, Air Force Research Laboratory, Department of Physics, Texas A\&M University, College Station, TX 77843, Department of Physics and MIC, Texas A\&M University, University of Texas at Arlington, Changwon National University, University of North Texas, Southwestern University, The Pennsylvania State University, University of Dallas, UT Southwestern Medical Center, Naval Air Systems Command, Institute for Quantum Studies and Department of Physics, Texas A\&M University, College Station, TX 77843, The University of Texas at Arlington, TCU, ELTE, National Institute of Chemistry, Ljubljana, Slovenia, Texas Christian University, Fort Worth, TX, Dept. of Physics, Texas A\&M University-Commerce, Univ. of North Texas, Los Alamos National Laboratory, Oswego State University of New York, Lee College, University of Texas at San Antonio, UTSA-Professor, UNT, Sam Houston State University, Sewanee: The University of the South, Director of Education for NSF, Center for Nonlinear Dynamics and Department of Physics, The University of Texas at Austin, Sackler School of Chemistry, Tel-Aviv University, Rice University, Department of Physics and Astronomy, Houston, TX 77005, Center for Nonlinear Dynamics, University of Texas at Austin

  • Edward Fry

    Institute for Astronomy, ETH, National Optical Astronomy Observatory, Department of Physics, ETH, Texas A&M University, LANL, American Physical Society, Society of Physics Students National Office, Texas Tech University, University of Texas, Universite d'Orleans, Steward Observatory, University of Arizona, Texas A\&M University-Commerce, Texas A\&M University, Institute for Quantum Electronics, ETH Zurich, Department of Engineering and Applied Science, Harvard University, Rice University, University of Houston, Bucknell University, Department of Physics, Texas A\&M University, Air Force Research Laboratory, Department of Physics, Texas A\&M University, College Station, TX 77843, Department of Physics and MIC, Texas A\&M University, University of Texas at Arlington, Changwon National University, University of North Texas, Southwestern University, The Pennsylvania State University, University of Dallas, UT Southwestern Medical Center, Naval Air Systems Command, Institute for Quantum Studies and Department of Physics, Texas A\&M University, College Station, TX 77843, The University of Texas at Arlington, TCU, ELTE, National Institute of Chemistry, Ljubljana, Slovenia, Texas Christian University, Fort Worth, TX, Dept. of Physics, Texas A\&M University-Commerce, Univ. of North Texas, Los Alamos National Laboratory, Oswego State University of New York, Lee College, University of Texas at San Antonio, UTSA-Professor, UNT, Sam Houston State University, Sewanee: The University of the South, Director of Education for NSF, Center for Nonlinear Dynamics and Department of Physics, The University of Texas at Austin, Sackler School of Chemistry, Tel-Aviv University, Rice University, Department of Physics and Astronomy, Houston, TX 77005, Center for Nonlinear Dynamics, University of Texas at Austin

  • Edward Fry

    Institute for Astronomy, ETH, National Optical Astronomy Observatory, Department of Physics, ETH, Texas A&M University, LANL, American Physical Society, Society of Physics Students National Office, Texas Tech University, University of Texas, Universite d'Orleans, Steward Observatory, University of Arizona, Texas A\&M University-Commerce, Texas A\&M University, Institute for Quantum Electronics, ETH Zurich, Department of Engineering and Applied Science, Harvard University, Rice University, University of Houston, Bucknell University, Department of Physics, Texas A\&M University, Air Force Research Laboratory, Department of Physics, Texas A\&M University, College Station, TX 77843, Department of Physics and MIC, Texas A\&M University, University of Texas at Arlington, Changwon National University, University of North Texas, Southwestern University, The Pennsylvania State University, University of Dallas, UT Southwestern Medical Center, Naval Air Systems Command, Institute for Quantum Studies and Department of Physics, Texas A\&M University, College Station, TX 77843, The University of Texas at Arlington, TCU, ELTE, National Institute of Chemistry, Ljubljana, Slovenia, Texas Christian University, Fort Worth, TX, Dept. of Physics, Texas A\&M University-Commerce, Univ. of North Texas, Los Alamos National Laboratory, Oswego State University of New York, Lee College, University of Texas at San Antonio, UTSA-Professor, UNT, Sam Houston State University, Sewanee: The University of the South, Director of Education for NSF, Center for Nonlinear Dynamics and Department of Physics, The University of Texas at Austin, Sackler School of Chemistry, Tel-Aviv University, Rice University, Department of Physics and Astronomy, Houston, TX 77005, Center for Nonlinear Dynamics, University of Texas at Austin

  • Edward Fry

    Institute for Astronomy, ETH, National Optical Astronomy Observatory, Department of Physics, ETH, Texas A&M University, LANL, American Physical Society, Society of Physics Students National Office, Texas Tech University, University of Texas, Universite d'Orleans, Steward Observatory, University of Arizona, Texas A\&M University-Commerce, Texas A\&M University, Institute for Quantum Electronics, ETH Zurich, Department of Engineering and Applied Science, Harvard University, Rice University, University of Houston, Bucknell University, Department of Physics, Texas A\&M University, Air Force Research Laboratory, Department of Physics, Texas A\&M University, College Station, TX 77843, Department of Physics and MIC, Texas A\&M University, University of Texas at Arlington, Changwon National University, University of North Texas, Southwestern University, The Pennsylvania State University, University of Dallas, UT Southwestern Medical Center, Naval Air Systems Command, Institute for Quantum Studies and Department of Physics, Texas A\&M University, College Station, TX 77843, The University of Texas at Arlington, TCU, ELTE, National Institute of Chemistry, Ljubljana, Slovenia, Texas Christian University, Fort Worth, TX, Dept. of Physics, Texas A\&M University-Commerce, Univ. of North Texas, Los Alamos National Laboratory, Oswego State University of New York, Lee College, University of Texas at San Antonio, UTSA-Professor, UNT, Sam Houston State University, Sewanee: The University of the South, Director of Education for NSF, Center for Nonlinear Dynamics and Department of Physics, The University of Texas at Austin, Sackler School of Chemistry, Tel-Aviv University, Rice University, Department of Physics and Astronomy, Houston, TX 77005, Center for Nonlinear Dynamics, University of Texas at Austin

  • Edward Fry

    Institute for Astronomy, ETH, National Optical Astronomy Observatory, Department of Physics, ETH, Texas A&M University, LANL, American Physical Society, Society of Physics Students National Office, Texas Tech University, University of Texas, Universite d'Orleans, Steward Observatory, University of Arizona, Texas A\&M University-Commerce, Texas A\&M University, Institute for Quantum Electronics, ETH Zurich, Department of Engineering and Applied Science, Harvard University, Rice University, University of Houston, Bucknell University, Department of Physics, Texas A\&M University, Air Force Research Laboratory, Department of Physics, Texas A\&M University, College Station, TX 77843, Department of Physics and MIC, Texas A\&M University, University of Texas at Arlington, Changwon National University, University of North Texas, Southwestern University, The Pennsylvania State University, University of Dallas, UT Southwestern Medical Center, Naval Air Systems Command, Institute for Quantum Studies and Department of Physics, Texas A\&M University, College Station, TX 77843, The University of Texas at Arlington, TCU, ELTE, National Institute of Chemistry, Ljubljana, Slovenia, Texas Christian University, Fort Worth, TX, Dept. of Physics, Texas A\&M University-Commerce, Univ. of North Texas, Los Alamos National Laboratory, Oswego State University of New York, Lee College, University of Texas at San Antonio, UTSA-Professor, UNT, Sam Houston State University, Sewanee: The University of the South, Director of Education for NSF, Center for Nonlinear Dynamics and Department of Physics, The University of Texas at Austin, Sackler School of Chemistry, Tel-Aviv University, Rice University, Department of Physics and Astronomy, Houston, TX 77005, Center for Nonlinear Dynamics, University of Texas at Austin

  • Edward Fry

    Institute for Astronomy, ETH, National Optical Astronomy Observatory, Department of Physics, ETH, Texas A&M University, LANL, American Physical Society, Society of Physics Students National Office, Texas Tech University, University of Texas, Universite d'Orleans, Steward Observatory, University of Arizona, Texas A\&M University-Commerce, Texas A\&M University, Institute for Quantum Electronics, ETH Zurich, Department of Engineering and Applied Science, Harvard University, Rice University, University of Houston, Bucknell University, Department of Physics, Texas A\&M University, Air Force Research Laboratory, Department of Physics, Texas A\&M University, College Station, TX 77843, Department of Physics and MIC, Texas A\&M University, University of Texas at Arlington, Changwon National University, University of North Texas, Southwestern University, The Pennsylvania State University, University of Dallas, UT Southwestern Medical Center, Naval Air Systems Command, Institute for Quantum Studies and Department of Physics, Texas A\&M University, College Station, TX 77843, The University of Texas at Arlington, TCU, ELTE, National Institute of Chemistry, Ljubljana, Slovenia, Texas Christian University, Fort Worth, TX, Dept. of Physics, Texas A\&M University-Commerce, Univ. of North Texas, Los Alamos National Laboratory, Oswego State University of New York, Lee College, University of Texas at San Antonio, UTSA-Professor, UNT, Sam Houston State University, Sewanee: The University of the South, Director of Education for NSF, Center for Nonlinear Dynamics and Department of Physics, The University of Texas at Austin, Sackler School of Chemistry, Tel-Aviv University, Rice University, Department of Physics and Astronomy, Houston, TX 77005, Center for Nonlinear Dynamics, University of Texas at Austin