•Nancy Boucharat, Harald Roesner und Gerhard Wilde
Forschungszentrum Karlsruhe, Institute of Nanotechnology, Postfach
3640, 76021 Karlsruhe
Nanocomposites consisting of nanoscale Pb or In particles dispersed
within a crystalline Al matrix have attracted particular attention since
considerable deviations in the Pb and In melting temperatures have been
observed compared to that of the bulk. Beyond the nano-size effect, several
proposals involving contributions of the crystalline matrix (e.g. grain
boundaries, strains and defects, lattice orientation relationship) have
been advanced to account for the modified melting behavior. Thus, the incorporation
of Pb and In nanoparticles in marginal glass formers gives a new opportunity
to wider the understanding of the impact of the matrix on the melting behavior,
especially to study the size-dependent melting behavior without the constraints
imposed on the particles by a crystalline matrix. Therefore, the melting
behavior of Pb and In nanoparticles embedded in rapidly quenched AlYFe
glass have been investigated by calorimetry and structural analyses. The
results indicate a general decrease of both melting temperatures. Moreover,
the shift of melting temperatures was found to be strongly correlated to
the matrix microstructure, i.e. whether the matrix is in an amorphous state,
contains Al-nanocrystal dispersions or is in a fully crystallised state.