Skip to main content
eScholarship
Open Access Publications from the University of California

UC San Diego

UC San Diego Electronic Theses and Dissertations bannerUC San Diego

Exploring Heavy Fermion Materials near a Quantum Critical Point

  • Author(s): Jang, Sooyoung;
  • et al.
Abstract

Results for two categories of heavy fermion systems : (1) a new type of non-centrosymmetric heavy fermion system R₂TM₁₂Pn₇ (R = rare earth, TM = transition metal, Pn = P, As), and (2) Yb substitution in CeCoIn₅, which is a heavy fermion superconductor, Ce₁-xYbxCoIn₅, are described. The phenomena seen in the system R₂TM₁₂Pn₇ are discussed in terms of strong hybridization between the localized f- electron states and the conduction electron states, such as a crossover between Fermi liquid and non-Fermi liquid behavior in Yb₂Ni₁₂P₇, or the presence of a large value of the Sommerfeld coefficient, [gamma] ̃ 650 mJ/mol Sm K² in Sm₂Ni₁₂P₇. The extraordinary electronic phenomena found in the system Ce₁-xYbxCoIn₅ include Yb valence fluctuations, a change in the Fermi surface topology, and suppression of the quantum critical field occurring at a nominal concentration of x ̃ 0.2. However, the suppression of the superconducting critical temperature with nominal Yb concentration x for bulk single crystals is much weaker than that observed in thin film samples. The actual Yb composition of bulk single crystals is found to be about 1 /3 of the nominal concentration, resolving the discrepancy between the variation of the physical properties of Ce₁- xYbxCoIn₅ single crystals and thin films with Yb concentrations

Main Content
For improved accessibility of PDF content, download the file to your device.
Current View