Bright field images of the palladium-based layer obtained with the solution of: (a) palladium sulfate; (b) palladium chloride; and (c) palladium nitrate, (insets: HRTEM images of CuPd nanoparticles composing these layers); (d) common SAED pattern of these three layers combined with a graph similar to an X-ray diffraction pattern which enables characterisation of the disordered CuPd alloy