WDS-EPMA nitrogen profile determination in TiN/Ti diffusion couples using homotypic standard materials

Wavelength-dispersive electron probe microanalysis (WDS-EPMA) of TiN/Ti diffusion couples was carried out in order to determine the nitrogen profiles across the phase bands. Thein situ TiN/Ti diffusion couples were used for phase equilibrium studies. The problem of complete overlap of the Ti_L1 and N_K lines was solved using chemically well-characterized single-phase titanium nitride samples (-Ti(N), -Ti₂N and -TiN_1–X) as external standards. By using such homotypic standard materials it was possible to eliminate systematic errors introduced by imperfect correction algorithms. The composition of the phases in multiphase TiN/Ti diffusion couples could be determined with an accuracy of better than ±1 at% N.