Thesis Defense

Thermodynamic and Transport Properties of Single Crystal YbNi4Cd

Friday, 20 July 2018 09:30AM PDT
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Thesis Defense
Thermodynamic and Transport Properties of Single Crystal YbNi4Cd

Jeonghun Lee
Department of Physics, SFU

July 20, 2018 at 9:30AM in P8445.2

Synopsis

The single crystal growth and the physical properties of the rare-earth based ternary intermetallic compounds RNi4Cd (R = Y and Yb) will be presented. The powder X-ray diffraction measurement reveals that these compounds crystallize in the face-centered cubic (fcc), MgCu4Sn-type structure (space group F-43m). Magnetization, electrical resistivity, and specific heat measurements are used to study thermodynamic and transport properties of YbNi4Cd. The magnetic susceptibility shows that 4f electrons of Yb3+ ions are well localized. The electrical resistivity and specific heat exhibits an antiferromagnetic ordering below TN = 0.97 K. Applying a field along [111] direction results in the suppression of TN below 0.4 K at the critical field Hc ~ 4.5 kOe. No non-Fermi liquid behavior is observed in the vicinity of Hc. Above Hc, the magnetoresistivity shows an unconventional temperature dependence ρ (T) = ρ0+ ATn with n > 2, suggesting that an additional scattering mechanism in the resistivity needs to be considered. Based on the analysis of experimental results, we conclude that the Yb3+ moments and conduction electrons are weakly coupled. Despite the antiferromagnetic ordering below TN, YbNi4Cd exhibits a large frustration parameter |θp/TN| ~ 16, where the magnetic Yb3+ ions occupy the tetrahedra on the fcc lattice.