Electric-field gradients at the Zr sites in Zr/sub 3/Fe : measured using perturbed-angular-correlation spectroscopy and calculated using band theory

• Autor(a) principal: Motta, Arthur T.
• Data de Publicação: 2002
• Outros Autores: Cumblidge, Stephen E., Catchen, Gary L., Legoas, Sergio B., Paesano Junior, Andrea, Amaral, Livio
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/103858
• topic: Estruturas de bandas; Gradiente de campo elétrico; Ligas de ferro; Correlacao angular perturbada; Ligas de zircônio

We have measured the electric-field-gradient (EFG) parameters Vzz and η and their temperature dependences at the two Zr sites in the intermetallic compound Zr₃Fe using perturbed-angular-correlation spectroscopy and the probe ¹⁸¹Hf→¹⁸¹Ta. At temperatures below the peritectic transformation at ≈1158 K, at each Zr site, we observed well-defined EFG’s, characterized by sharp spectral lines. A high-frequency, very asymmetric nuclear electric-quadrupole interaction characterizes the first Zr site, which represents approximately one-third of the probes. A low-frequency, nearly axially symmetric nuclear electric-quadrupole interaction characterizes the second Zr site, which represents approximately two-thirds of the probes. Near and above the peritectic transformation, the results show the effects of the decomposition of Zr₃Fe into Zr and Zr₂Fe and subsequent melting. We have compared the values of Vzz and h measured at laboratory temperature to those calculated using the first-principles, self-consistent real-space linear muffin-tin atomic sphere approximation (RS-LMTOASA) band-theory method. Overall the magnitudes of Vzz and η calculated using the RS-LMTO-ASA method agree reasonably well with the experimental values.