Structural characterization of the and compounds by means of hyperfine interaction studiesP. Wodniecki1, 2, A. Kulinska1, 2, B. Wodniecka1, S. Cottenier3, 4, H. M. Petrilli4, M. Uhrmacher2 and K. P. Lieb2
1 IFJ PAN, 31-342 Krakow, Poland
2 II. Physikalisches Institut, Universität Göttingen - Friedrich-Hund-Platz 1, D-37077 Göttingen, Germany
3 Instituut vor Kern- en Stralingsfisica, K. U. Leuven - Celestijnenlaan 200 D, B-3001 Leuven, Belgium
4 Instituto di Fisica, Universidade de Sao Paulo - CP 66318, 05315-970, Sao Paulo, SP, Brazil
received 10 November 2006; accepted in final form 20 December 2006; published February 2007
published online 9 February 2007
Electric-field gradients have been measured in the isostructural intermetallic compounds and , using radioactive Ta hyperfine probes. In both compounds, two well-defined electric-field gradients have been observed, whose temperature dependence follows the T3/2 rule in the temperature range 301170 K. Using the full-potential augmented plane-wave + local-orbitals formalism, the electric-field gradients have been calculated. On the basis of the 181Ta hyperfine interaction parameters, the possible Hf/Zr lattice sites have been assigned. In this way the controversy concerning the lattice structure of these compounds deduced from X-ray diffraction has been solved.
31.30.Gs - Hyperfine interactions and isotope effects, Jahn-Teller effect.
61.18.-j - Other methods of structure determination.
61.72.-y - Defects and impurities in crystals; microstructure.
© Europhysics Letters Association 2007