YbNiSi3: a new antiferromagnetic Kondo lattice with strong exchange interaction

TL;DR

This paper reports the discovery and characterization of YbNiSi3, a new antiferromagnetic Kondo lattice with strong exchange interactions and high ordering temperature, exhibiting heavy-electron behavior and anisotropic resistivity.

Contribution

It introduces YbNiSi3 as a new compound with detailed structural, thermodynamic, and transport properties, highlighting its strong exchange interaction and high magnetic ordering temperature.

Findings

YbNiSi3 has an antiferromagnetic transition at 5.1 K.

The compound exhibits heavy-electron behavior with a Sommerfeld coefficient of 190 mJ/mol K^2.

Resistivity shows anisotropic behavior with a logarithmic increase and a sharp decrease below the ordering temperature.

Abstract

We report on the structural, thermodynamic and transport properties of high-quality single crystals of YbNiSi3 grown by the flux method. This compound crystallizes in the SmNiGe3 layered structure type of the Cmmm space group. The general physical behavior is that of a Kondo lattice showing an antiferromagnetic ground state below T_N = 5.1 K. This is among the highest ordering temperatures for a Yb-based intermetallic, indicating strong exchange interaction between the Yb ions, which are close to +3 valency based on the effective moment of 4.45 mu_B/f.u. The compound has moderately heavy-electron behavior with Sommerfeld coefficient 190 mJ/mol K^2. Resistivity is highly anisotropic and exhibits the signature logarithmic increase below a local minimum, followed by a sharp decrease in the coherent/magnetically ordered state, resulting in residual resistivity of 1.5 micro Ohm cm and RRR = 40. Fermi-liquid behavior consistent with a ground-state doublet is clearly observed below 1 K.