Contrasted morphologies in nanostructured Janus W-Cu columns

Janus-like W-Cu films exhibiting a tilted columnar architecture are prepared by GLAD co-sputtering using W and Cu targets. Co-deposition of these two-immiscible metals leads to contrasted morphologies in the columns growth. Observations scanning electron microscopy reveal different structural features at micro- nanoscales as face or target. In front flux, dense with saw-tooth profile, whereas granular rough aspect is produced for opposite side receiving atoms. A finer analysis high resolution transmission supports morphologies. Growth mechanisms well occurrence diverse crystallographic phases (bcc α-W, fcc even disordered WxCu1-x alloy despite immiscibility metals) through cross-section discussed.