Suppression of B2 phase in PdzCu1-z alloy thin films

Abstract Thin films of pure metals and alloys can adopt phases that differ from those of the corresponding bulk alloy phase diagram. In the bulk, Pd z Cu 1- z adopts a B2 phase (CsCl structure) for 0.35  z z Cu 1- z alloys with thickness p 3/2 core level shifts (CLS, ∆E CLS Cu ( z )) across a Pd z Cu 1- z composition spread alloy film (CSAF) as a function of both composition and film thickness. In the FCC phase, the Cu 2 p 3/2 binding energy decreases monotonically across the range z  = 0 → 1. At T z p 3/2 CLS can be used to distinguish between the B2 and FCC phases. After annealing the Pd z Cu 1- z CSAF to 700 K, the bulk B2 phase was observed at film thicknesses >6 nm. However, at film thicknesses in the range 4–6 nm, only the FCC phase was observed. Stabilization of the FCC phase for films that are