Possible structural quantum phase transition in UCr<sub>2-<i>x</i></sub>Ru<i><sub>x</sub></i>Si<sub>2</sub>
ORAL
Abstract
We report an investigation of the structural, thermodynamic, and electrical transport properties of the chemical substitution series UCr2-xRuxSi2. UCr2Si2 is an unusual Kondo lattice metal that shows antiferromagnetism at TN = 27 K, a structural phase transition from tetragonal (I4/mmm) to triclinic (P) near Ts = 210 K, and a so-far unidentified phase transition near TM = 275 K. Cr → Ru substitution results both in expansion of the unit cell volume and filling of the d-shell, causes TN and TS to be suppressed to zero temperature near xcr ≈ 0.075 and 0.13, respectively. In contrast, TM disappears immediately with small amount of Ru. In the critical region, there is evidence for non-Fermi liquid behavior, (i) a weak logarithmic divergence in the electronic component of the heat capacity divided by temperature and (ii) a sub-quadratic temperature dependence of the electrical resistivity. Thus, we suggest that this may be a model system for studying a lattice instability at zero temperature, its relationship to a nearby antiferromagnetic quantum phase transition, and the resulting impact on electronic properties and lattice modes in a strongly correlated electron metal.
*This work is supported by NSF under No. DMR-1644779 and the State of Florida, and DOE under Award No. DE-SC0016568.
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Presenters
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You Lai
- Florida State University
- National High Magnetic Field Laboratory