EELS (electron energy loss spectrometry) in the transmission electron
microscope (TEM) was used to determine the
composition of a nanocrystalline magnetic specimen. The relative amounts
of the hard magnetic phase Nd2Fe14B and the soft magnetic phase Fe3B at
the point of measurement was measured by standard EELS quantification. In
order to determine the structure of Fe3B present, the fine
structure of the boron K-ionisation edge was analysed. Comparison of the
experimental spectra with simulations of the fine structures based on the
TELNES extension of the WIEN97 program package, a full potential
linearised augmented plane wave approach to the calculation of
electronic structure in crystals, shows that the tetragonal form of
Fe3B is predominant.