Characterization of sputter-deposited multilayers of Ni and Zr with APFIM/TAP

Thin layers of Ni and Zr (Ni/Zr/Ni) were grown on well developed tungsten and nickel FIM tips under ultra-high vacuum conditions by sputter deposition at room temperature. The amount of Ni deposited was equivalent to about 20 nm thickness, whereas that of the intermediate Zr layer varied between 10 and 30 nm. These specimens were investigated by means of Atom Probe Field Ion Microscopy (APFIM) and Tomographic Atom Probe (TAP). The specimen with the thinner Zr film (5–20 nm) showed no sharp interface, but a transient region between the Ni and Zr films. For specimen with the thick Zr films (≥ 20 nm) both the transient region and pure Zr layers were observed. Both the spatial variation of the composition and the structure of this intermediate region were investigated. The results indicate that the transient region is partially amorphous.