A New Look at Bonding in Trialuminides: Reinvestigation of TaAl3

Single crystals of TaAl3 were grown at high temperatures from an Al-rich, binary solution. TaAl3 adopts the D022 structure type, space group I4/mmm with a = 3.8412(5) Å, c = 8.5402(17) Å, and Z = 2. The structure type, which is the preferred structure for all group 5 trialuminides and TiAl3 as well as the high-temperature form of HfAl3, is a binary coloring of the face-centered-cubic (fcc) arrangement. The distribution of Ta atoms creates a three-dimensional network of vertex and edge-sharing square pyramids of Al atoms. Temperature-dependent electrical resistivity and magnetic susceptibility measurements are consistent with TaAl3 being a metallic compound with a relatively low density of states at the Fermi surface. Furthermore, tight-binding electronic structure calculations are utilized to describe the bonding in these compounds and to compare their stability with respect to the alternative fcc-related, e.g., the D023 (ZrAl3-type) and the L12 (AuCu3-type), structures. A modified Wade\u27s rule argument provides insights into the structural preferences

A New Look at Bonding in Trialuminides: Reinvestigation of TaAl3

Single crystals of TaAl3 were grown at high temperatures from an Al-rich, binary solution. TaAl3 adopts the D022 structure type, space group I4/mmm with a = 3.8412(5) Å, c = 8.5402(17) Å, and Z = 2. The structure type, which is the preferred structure for all group 5 trialuminides and TiAl3 as well as the high-temperature form of HfAl3, is a binary coloring of the face-centered-cubic (fcc) arrangement. The distribution of Ta atoms creates a three-dimensional network of vertex and edge-sharing square pyramids of Al atoms. Temperature-dependent electrical resistivity and magnetic susceptibility measurements are consistent with TaAl3 being a metallic compound with a relatively low density of states at the Fermi surface. Furthermore, tight-binding electronic structure calculations are utilized to describe the bonding in these compounds and to compare their stability with respect to the alternative fcc-related, e.g., the D023 (ZrAl3-type) and the L12 (AuCu3-type), structures. A modified Wade's rule argument provides insights into the structural preferences.Reprinted (adapted) with permission from Inorg. Chem., 2003, 42 (25), pp 8371–8376. Copyright 2003 American Chemical Society.</p

Anomalous temperature-dependent transport in YbNi2B2C and its correlation to microstructural features

We address the nature of the ligandal disorder leading to local redistributions of Kondo temperatures, manifested as annealing-induced changes in the transport behavior of the heavy fermion system YbNi2B2C. The anomalous transport behavior was fully characterized by temperature dependent resistivity measurements in an extended range of 0.4This article is from Physical Review B 69 (2004): 1, doi:10.1103/PhysRevB.69.205107. Posted with permission.</p