FABRICATION AND CHARACTERIZATION OF FUNCTIONALLY GRADED Ni–Ti MULTILAYER THIN FILMS
2009 ◽
Vol 02
(02)
◽
pp. 61-66
◽
Keyword(s):
A functionally graded multilayer Ni – Ti thin film was deposited on a SiO 2/ Si substrate by d.c. sputtering using a ramped heated Ni – Ti alloy target. The stand-alone films were crystallized at 500°C in vacuum better than 10-7 Torr. Transmission electron microscopy micrographs taken along the film cross section show two distinct regions, thin and thick, with weak R and B2 phases, respectively. The film compositions along the thickness were measured and quantified using the standard-less EELSMODEL method. The film deposited during the initial thermal ramp (thin regions) displays an average of 54 at.% Ni while the film deposited at a more elevated target temperature (thick regions) shows about 51 at.% Ni .