Oxygen-induced Y surface segregation in a CuPdY ternary alloy

► We study the segregation behavior of CuPdY in vacuum and oxygen rich-environments. ► DFT predicts that Y subsurface segregates in presence of vacuum. ► XRD characterization of CuPdY surface indicates the presence of two major phases. ► In presence of oxygen, Y segregates and forms Y-oxides at the top-surface of CuPdY.