Doping induced quantum phase transition in the itinerant ferromagnet scandium indium
Master of Science
Examination of quantum critical points of itinerant electron systems will aid with understanding of d-electron magnetism that exhibits both local and itinerant characteristics in different families of compounds. Doping-induced quantum phase transition of the itinerant ferromagnet Sc 3.1 In that is composed of non-magnetic elements is the focus of our work. Polycrystalline samples of (Sc 1-x Lu x ) 3.1 In with 0≤ x≤ 0.08 were prepared by arcmelting and then annealing for an extended period of time. Susceptibility measurements were performed in an applied magnetic field H = 0.1 T for temperatures T = 1.85 K to 300 K. Linearity of Arrott plots in low-field region was significantly improved by implementing the non-mean-field Arrott-Noakes technique where plotting M 1/β vs. ( H/M ) 1/γ is used to determine both the Curie temperature and composition. Modified Arrott plot approach was used in order to determine the new critical exponents β, γ and δ that better describe this compound. The Curie temperature of the Sc 3.1 In compound was found to be T C = 4.4 K and the critical composition x c = 0.02. This work was supported by NSF DMR 0847681.
Pure sciences; Electromagnetics; Condensed matter physics