In the quest for superlattices with engineered interfaces for disruptive applications such as neuromorphic computing, we present a dedicated study on the epitaxial growth of nominal GeTe/Sb2Te3 chalcogenide superlattices (CSL) on the Sb passivated Si(111) - (root 3 x root 3)R30 degrees - Sb surface. Intermixing at the GeTe and Sb2Te3 interface is assessed by X-Ray diffraction and reflectivity. A new growth procedure with element flux interruptions is proposed to engineer the degree of intermixing and the tailoring of the GeSbTe layers into Sb-rich compositions.