Competition between Superconductivity and Charge Density Wave Ordering in the Lu$_5$Ir$_4$(.pdf

Competition between Superconductivity and Charge Density Wave Ordering in the Lu Ir (Si Ge ) Alloy System 5 4 1−x x 10 5 0 Yogesh Singh, R. Nirmala, S. Ramakrishnan and S. K. Malik 0 2 Tata Institute of Fundamental Research, Mumbai-400005, India y a Abstract M We have performed bulk measurements such as dc magnetic susceptibility, electrical resistivity 9 1 and heat capacity on the pseudo-ternary alloys Lu Ir (Si Ge ) to study the interplay and 5 4 1−x x 10 ] competition between superconductivity and the charge density wave (CDW) ordering transition. l e - r We track the evolution of the superconducting transition temperature TSC and the CDW ordering t s t. temperature TCDW as a function of x (concentration of Ge) (0.0 ≤ x ≤ 1.0). We find that a m increasing x (increasing disorder) suppresses the TCDW rapidly with the concomitant increase in - d TSC . We present a temperature-concentration (or volume) phase diagram for this system and n o compare our results with earlier work on substitution at the Lu or Ir site to show how dilution at c [ the Si site presents a different situation from these other works. The heat capacity data in the 1 v vicinity of the CDW transition has been analyzed using a model of critical fluctuations in addition 3 6 to a mean-field contribution and a smooth lattice background. We find that the critical exponents 4 5 change appreciably with increasing disorder. This analysis suggests that the strong-coupling an