Extension of PROZA96 to conditions of non-perpendicular incidence of the electron beam.

An extension of our double Gaussian PROZA96 correction program for EPMA is presented, which can handle non-perpendicular incidence of the electron beam. The description of the changes in the primary intensity generated in the specimen and of the changes in the integral of ( z) with tilt are taken from the literature. The extreme changes in the shape of ( z) are modeled by a gradual transition of the original double Gaussian shape at zero tilt, through a mixed Gaussian/single-exponential (for tilt angles up to 60°), to finally a mixed Gaussian/double-exponential shape (for tilt angles exceeding 60°). The left-hand (rising) branch of ( z) is assumed to retain its original Gaussian form during tilting. Tests on the limited data available in the literature have shown that the performance of this new extended model is very promising. Copyright © 2001 John Wiley & Sons, Ltd

Wavelength- and energy-dispersive Electron Probe Microanalysis (EPMA) measurements with non-perpendicular incidence of the electron beam

A database of 416 wavelength- and energy-dispersive EPMA measurements on tilted specimens of NiAl, TiO2 and Ti3Al is presented. The analyses were performed between 10 and 30 kV and the tilt angles were varied between 0° and 60° in seven steps. The necessary hardware modifications for the specimen holder are discussed, as well as the various focusing techniques used in the measurements. A comparison between the experimental data, the calculations of our proza96t program and the results of Monte Carlo simulations shows that up to 50° tilt the predictions of our software are more than satisfactory. At larger tilt angles some deviations become noticeable. The Monte Carlo simulations appear to produce deviations at a somewhat earlier stage already, for reasons as yet unknown

Solid State Diffusion in the Bi-Pd System

Growth of intermetallic compounds in the Bi-Pd system during solid state diffusion was studied since this system gains relevance for the electronic industry where Pd is used as a protective coating on substrates in combination with lead-free solders (containing Bi.This system is still not completely established, especially on the Pd-rich side of the system, and no diffusion studies have been performed yet.In the present work diffusion couples of Bi and Pd were investigated after annealing for various times (96h-1000h) in the temperature range 200-250°C, to establish the growth kinetics of the intermetallic phases.It was found that the total layer thickness grows parabolically with time, which implies a diffusion-controlled process.The intermediate phase gamma, which forms below 400°C, was found to exist as a stable phase at a temperature down to 200°C. In order to confirm the existence of this phase at low temperature an equilibrated Bi/Pd alloy was examined. The composition of the gamma-phase was found to be 62.4 at %of Pd.This phase was also observed in an incremental diffusion couple of BiPd/Pd after annealing. Another intermetallic layer is that couple, although thin, was identified as the BiPd3 intermetallic. The latter phase was not reported to be stable at such low temperatures. Integrated diffusion coefficients for gamma-phase, BiPd and Bi were determined at different temperatures

Phase relations in the Bi-Ni-Pd system at 235°C.

The Bi-Pd and Ni-Bi binary phase equilibria at 235 °C were investigated. It was concluded that Bi2Pd, BiPd, Bi3Pd5, and BiPd3 are stable intermetallics in the Bi-Pd system and NiBi and NiBi3 are stable in the Ni-Bi system at this temperature. An isothermal cross section of the ternary Ni-Bi-Pd system at the same temperature was established experimentally. No ternary compound has been found. However, the Pd-rich corner of the phase diagram cannot be determined due to the sluggishness of the kinetics involved