We report on growth, morphology and magnetic behavior of the pseudo spin-valve (PSV) Si/Co(15 nm)/Sn(50 nm)/Co(15 nm). Thermal evaporation was chosen as experimental deposition technique for its versatility and cost effectiveness. Magnetisation and magnetotransport measurements performed at low temperature showed that the sample has a complex behaviour related to the different morphology and thickness of the outer Co layers. Combining magnetic and magnetotransport data, a model based on three magnetic phases has been developed, associating them to the Co underlayer, to the Co cap layer and to possible nanometre-sized Co islands embedded in the Sn layer, respectively. A three-phase model coherently explains both magnetisation and magnetoresistance datasets.