Confined sulfur between two multilayer graphene films under thermal treatments by means of electrical and Raman spectroscopy characterization was studied. Similarities between the electrical behavior and calorimetry of sulfur immersed into nanoporous alumina during sulfur phase transitions suggest that sulfur has a different thermal behavior when it is in confinement conditions compared to the free state. Additionally, reaction of sulfur with multilayer graphene at 500 degrees C produced covalent bonds and a p-type doping of about 2 x 10(13) cm(-2) in charge concentration. (C) 2016 Elsevier B.V. All rights reserved.