Electric field gradients in (111)In-doped (Hf/Zr)(3)Al(2) and (Hf/Zr)(4)Al(3) 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. The effects of the size of the supercell and relaxation around the oversized In and Cd probe atoms were investigated in detail.

Agencia Nacional de Promoción Científica y Tecnológica (ANPCyT)

ANPCyT Agencia Nacional de Promocion Cientifica y Tecnologica (ANPCyT)[PICT98 0303727]

Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET)[PIP6032]

Consejo Nacional de Investigaciones Científicas y Técnicas de Argentina (CONICET)

Consejo Nacional de Investigaciones Científicas y Técnicas de Argentina (CONICET)

Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET)[0002]

Antorchas, Argentina, and Third World Academy of Sciences (TWAS), Italy[RGA 97-057]

The World Academy of Sciences (TWAS) for the advancement of science in developing countries

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Cnpq

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fapesp

Capes (Brazil)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Deutsche Forschungsgemeinschaf (DFG)

Deutsche Forschungsgemeinschaft (DFG)

Deutscher Akademischer Austauschdienst (DAAD)

Deutscher Akademischer Austauschdienst (DAAD)

Serbian Ministry of Science

Serbian Ministry of Science