title: Is the negative temperature coefficient of the resistivity of the quasicrystals due to chemical disorder?
abstract: We have found that the electronic transport of the binary icosahedral (i) Cd-Yb is extremely sensitive to a minute substitution of Mg for Cd atoms; the positive temperature coefficient of the resistivity (TCR) at low temperatures seen in the binary i Cd-Yb disappears by addition of only 0.1 at. % Mg and, moreover, the TCR stays negative well up to 60 at. % Mg. Such sensitiveness of the resistivity in the very dilute Mg concentration region, which is a consequence of the long coherence length (>28 A) of the conduction electrons in the quasiperiodic lattice, has led us to an unexpected conclusion: The negative TCR in the ternary i phase is due to partial chemical disorder; i.e., it is not a consequence of the quasiperiodicity.
authors.affiliation: Department of Materials Science and Technology, Tokyo University of Science, Noda, Chiba 278-8510, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Tamura
authors.forename: T
authors.initials: T
authors.lastname: Araki
authors.forename: S
authors.initials: S
authors.lastname: Takeuchi