Comparative analysis of SnTe films: Protecting topological surface states with <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>Ba</mml:mi><mml:msub><mml:mi mathvariant="normal">F</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math> cap layer

This work presents a comparative analysis of tin telluride (SnTe) films with and without the protection of a cap layer that was implemented to protect from oxidation the topological surface states on the SnTe. The implementation of the cap layer aims to overcome a major issue that poses a challenge to the implementation of topological insulators for development of operational spintronic devices. Analysis involves a detailed investigation of the Shubnikov--de Haas oscillations and extracting the Berry phases that indeed indicate the presence of Dirac fermions in the capped sample. The introduction of the cap layer was successful in preserving the structural quality of the sample and, at the same time, maintaining the crystalline symmetries responsible for protecting the topological surface states.