[en] Contaminants like oxygen, carbon etc. in NiTi thin film have adverse effects on the transformation temperature. Hence, determination and minimizing the concentrations of these impurities in NiTi films are crucial. In the present work, NiTi thin films of different concentration and thickness were synthesized using cosputtering process of magnetron sputtering system utilizing separate Ni and Ti targets. Thickness and density of the films measured by XRR technique was used for determining the relative atomic density of Ni and Ti considering the fact that only Ni and Ti are presents in the films. Atomic fractions of Ni and Ti were also determined by EDS and compared with XRR technique. SIMS technique has been used for determining the oxygen impurity distribution in the film. (author)