Probing the electronic properties of ternary A MB ( = 1: A = Ca, Sr; M = Rh, Ir and = 3: A = Ca, Sr; M = Rh) phases: observation of superconductivity.

We follow the evolution of the electronic properties of the titled homologous series when as well as the atomic type of A and M are varied where for = 1, A = Ca, Sr and M = Rh, Ir while for = 3, A = Ca, Sr and M = Rh. The crystal structure of = 1 members is known to be CaRhB-type (), while that of = 3 is CaRhB-type (); the latter can be visualized as a stacking of structural fragments from AMB (6/) and AMB. The metallic properties of the = 1 and 3 members are distinctly different: on the one hand, the = 1 members are characterized by a linear coefficient of the electronic specific heat ≈ 3 mJ mol K, a Debye temperature ≈ 300 K, a normal conductivity down to 2 K and a relatively strong linear magnetoresistivity for fields up to 150 kOe.

Electric field gradients in (111)In-doped (Hf/Zr)3Al2 and (Hf/Zr)4Al3 mixed compounds: ab initio calculations, perturbed angular correlation measurements and site preference.

The quadrupolar hyperfine interactions of in-diffused (111)In --> (111)Cd probes in polycrystalline isostructural Zr(4)Al(3) and Hf(4)Al(3) samples containing small admixtures of the phases (Zr/Hf)(3)Al(2) were investigated. A strong preference of (111)In solutes for the contaminant (Zr/Hf)(3)Al(2) minority phases was observed. Detailed calculations of the electric field gradient (EFG) at the Cd nucleus using the full-potential augmented plane wave + local orbital formalism allowed us to assign the observed EFG fractions to the various lattice sites in the (Zr/Hf)(3)Al(2) compounds and to understand the preferential site occupation of the minority phases by the (111)In atoms.

Hyperfine interaction studies with (181)Ta and (111)Cd probes in the compound Ti(2)Ag.

By using the time-differential perturbed angular correlation technique, the electric field gradients (EFG) at (181)Hf/(181)Ta and (111)In/(111)Cd probe sites in the MoSi(2)-type compound Ti(2)Ag have been measured as a function of temperature in the range from 24 to 1073 K. Ab initio EFG calculations have been performed within the framework of density functional theory using the full-potential augmented plane wave+local orbitals method as implemented in the WIEN2k package. These calculations allowed assignments of the probe lattice sites.