Study of martensitic transformation in a CuZnAl shape memory alloy using photoemission

The thermally-induced martensitic transformation in a polycrystalline CuZnAl shape memory alloy (SMA) was probed using photostimulated electron emission (PSE) and ultra-violet photoelectron spectroscopy (UPS). UPS measurements of the apparent surface work function during heating show distinct differences that we attribute to electronic structure changes associated with the transformation. In situ photoelectron emission intensities during heating also show distinctive changes that can be accounted for on the basis of the change in work function. In-situ photoemission measurements can provide quantitative, spatially resolved information on surface fraction of austenite and martensite phases as the transformation proceeds.