Influence of Anomalous Changes in the Crystal Structure on the Transport Properties of YbNi1−xCuxAl Series of Alloys

Abstract

Results of the transport properties of the YbNi1−xCuxAl (x = 0, 0.2, 0.5, 0.8 and 1.0) series of alloys are reported. The previous analysis of X-ray diffraction patterns indicates that all compounds crystallize in the hexagonal ZrNiAl structure with a linear behavior of the unit cell volume as a function of the Cu concentration (x). This is not found in the unit cell parameters, showing a discontinuity between x = 0.5 and 0.8. Such discontinuities affect the behavior of the electrical resistivity, in which the position of the minimum temperature changes from 95 K to 175 K, and a rise in the low temperature slope in the magnetic contribution (with -lnT dependence) from 21 μΩcm to 212 μΩcm is observed. In addition, the electronic coefficient of the specific heat increases almost twofold from 125 mJ/mol·K2 (x = 0.5) to 246 mJ/mol·K2 (x = 0.8). These changes are attributed to the variation of the distance between Yb and transition metals (Ni and Cu) along the series and the different electronic properties of the transition metals (Ni and Cu).

A Canonical Transformation for the Anderson Lattice Hamiltonian with F-F Electron Coupling

“…The new Kondo lattice Hamiltonian had been used to study the anomalous temperature dependence of the electrical resistivity in the Kondo lattice intermetallic compound such as CeCu 6 , by using the Green's function method and numerical computations, and the obtained numerical result was consistent with the experimental data of CeCu 6 [43]. The new Kondo lattice Hamiltonian may also be used to study some anomalous physical properties in other Kondo lattice intermetallic systems [44][45][46][47][48], e.g., Kondo spin compensated state, or the state with local magnetic moments quenched at low temperature.…”

A Canonical Transformation for the Anderson Lattice Hamiltonian with f–f Electron Coupling

“…The new Kondo lattice Hamiltonian had been used to study the anomalous temperature dependence of the electrical resistivity in the Kondo lattice intermetallic compound such as CeCu 6 , by using the Green's function method and numerical computations, and the obtained numerical result was consistent with the experimental data of CeCu 6 [43]. The new Kondo lattice Hamiltonian may also be used to study some anomalous physical properties in other Kondo lattice intermetallic systems [44][45][46][47][48], e.g., Kondo spin compensated state, or the state with local magnetic moments quenched at low temperature.…”