QMS-CONTROLLED PRODUCTION OF NANOCRYSTALLINE METALS BY INERT-GAS CONDENSATION IN A FLOW SYSTEM

Nanocrystals of about 40 nm in size are produced by evaporation of zin c in a flow system. The metal atom concentration is monitored in relat ion to the argon carrier by a quadrupole mass spectrometer. The aggreg ation kinetics are observed on a time scale of 10-100 ms by varying th e distance between evaporation source and mass spectrometer inlet. Sev eral grams of the resulting metal powder were retained in a filter and studied by powder diffraction, neutron small angle scattering and sca nning electron microscopy.