Transmission electron microscope study of the topotactic reaction of (0 0 1), (0 1 1) and (1 1 1) Ag films and Te

The formation, structure and morphology of silver telluride was investigated in the reaction of (0 0 1), (0 1 1) and (1 1 1) single crystalline Ag films with vacuum deposited Te. Silver films 30-40 nm in thickness were deposited by thermal evaporation onto water- and chlorine-treated NaCl. Onto this silver 1-40 nm of tellurium were deposited at 100 and 200 deg. C. The Ag-Te reaction occurred during Te deposition. Accordingly, formation of the compound phase was investigated from the nucleation stage through complete tellurization on either side of the polymorphic phase transformation temperature (Tc=150 deg. C). Transmission electron microscope and selected area electron diffraction showed that monoclinic silver telluride (Ag2Te) of different morphology and texture was always formed. The orientation of silver and monoclinic phase upon differently oriented monocrystalline Ag films and at deposition temperatures around Tc is discussed