The theoretical calculations indicated that the monoclinic low-temperature phase of silver telluride (β -Ag2 Te) is a new binary topological insulator with highly anisotropic single Dirac cone surface. We obtained β -Ag2 Te crystal ingots containing few grains by the Bridgman method. We also deposited thin films of tellurium, Ag5 Te3 and (Te+Ag5 Te3) by thermal evaporation method. The Raman spectra of β -Ag2 Te, tellurium and Ag 5 Te3 were measured at three excitation wave lengths: 633, 515 and 488 nm. The Raman active modes of β -Ag2 Te, tellurium and Ag5 Te3 are situated at frequencies below 300 cm -1 while vibrations of other phases appear at higher frequencies.
- Raman spectroscopy
- Single crystals
- Thin films
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