Gold-Alumina nano composite thin films were prepared by RF-magnetron sputtering technique on glass substrate at room temperature. Subsequent thermal treatment was used to promote gold nano clusters formation. After annealing, an increase of size accompanied by an increase of the lattice constant parameter is observed. A value of the surface stress coefficient of gold is f = 3.11 N/m has been obtained and a value of lattice thermal expansion coefficient of gold 𝛼_{𝑔𝑜𝑙𝑑}(𝑇)=2.6 x 10−5/°C is achieved. Broad band absorption with maximum absorbance at around 500 nm characteristic of gold nanoclusters was observed after heat treatment. Experimental optical absorption spectra were modeled by the modified Mie theory. A red sift of the plasmon peak is obtained with increasing the annealing temperature.

Keywords: Au Nanoparticles; Lattice Parameter; Thermal Expansion;