Hyperfine study of mechanically induced transformations in solids

F.H. SÁNCHEZ, C.E. RODRÍGUEZ TORRES, A.F. CABRERA, M. MEYER, L. MENDOZA ZÉLIS AND M.B. FERNÁNDEZ VAN RAAP

JOURNAL OF METASTABLE AND NANOCRYSTALLINE MATERIALS

TRANS TECH PUBLICATIONS LTD

Año: 1999 vol. 269 p. 443 - 448

1422-6375

Preliminary results on order-disorder transformations in mechano-synthetised Fe75Ge25 and Fe60Al40, as well as on tools contamination of elemental samples, are presented. In the first case the system forms in the disordered cI2-W structure, but orders into the cF16-BiF3 structure when treated a T £ 673 K, or into the hP8-Ni3Sn one when annealed at 1073 K. Mechanical work induces the hP8-Ni3Sn structure to transform back into the cI2-W one. Disordering by mechanical work of cP2-CsCl-type Fe60Al40, gives raise to the apparition of magnetic hyperfine interactions in the RT Mössbauer spectra. Tool contamination of elemental samples treated in a planetary mill with chrome steel vials and balls could be tentatively described in terms of their Poisson ratio, rather than in terms of either their Young, shear or bulk moduli, or of the Fe-element enthalpy of mixing.