Study of phase formation of high fluence oxygen ion-implanted titanium and molybdenum by means of in-situ electrical resistance measurements

Oxygen and argon ion implantations into molybdenum and titanium thin films on sapphire have been performed at room temperature and higher temperatures (<550°C). Electrical resistance measurements were carried out in-situ in a four-point probe assembly. The resistance data obtained were refined by applying a parallel coupling model in order to separate the resistance value of the implanted region. Furthermore, the resistance change over the whole implantation process was mapped to values of transformed volume fraction. Finally, Avrami plots yielded Avrami exponents ≤1, which are explained due to inhomogenities in the transformation process and also as a result of a diffusion controlled kinetic caused by a ballistic mechanism. Clear differences between implantation at room temperature and high temperatures and also between argon and oxygen implantation are obtained.