Research Projects

The equilibrium phase diagram of the Cu-Nb binary system shows limited solid solubility between Cu and Nb. In recent decades, attempts have been made to create metastable nanocrystalline Cu-Nb alloys and nanocomposites using non-equilibrium synthesis methods. These metastable alloys exhibit improved mechanical strength and moderately high electrical conductivity at room temperature. However, the Nb composition range depends on the alloy synthesis method. Mechanical alloying allows for up to 10% Nb composition, while physical vapour deposition methods have reported nanocrystalline and amorphous Cu-Nb alloy thin films over a wide range of Nb compositions. These metastable alloy films possess higher Gibbs free energies, which may undergo phase separation during post-deposition annealing or film deposition. The study of thermal stability in nanocrystalline Cu-Nb alloy films must consider temperature-dependent microstructure evolution, stress development, and crystallographic texture changes. The project proposes detailed investigation of alloy formation, thermal stability, and phase separation mechanism in sputter deposited Cu100-x-Nbx thin films using in-situ high temperature and ex-situ X-ray diffraction (XRD), differential scanning calorimetry (DsC), high resolution transmission electron microscopy (HR-TEM), and atom probe tomography (APT).