Espectroscopia de campo-próximo em sistemas bidimensionais

• Ano de defesa: 2012
• Autor(a) principal: Rodolfo Vieira Maximiano
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Campo-próximo; Espectroscopia Raman; Materiais bidimensionais; Raman, Efeito intensificado em superficies; Física
• Link de acesso: http://hdl.handle.net/1843/MPDZ-8WSQAS

A theory describing the near-field Raman enhancement in two-dimensional (2D) systems is presented. The analysis quanties the near-field Raman intensity as a function of the tip-sample distance, Raman polarizability tensor components, incident laser beam configuration, and tip orientation relative to the sample plane. Our results show that the near-field Raman intensity is inversely proportional to the 10th and 8th power of the tip-sample distance in the incoherent and coherent scattering regimes, respectively. Optimal conditions for the tipinclination angle for different congurations are determined, and the results can be used as a guide for TERS experiments in 2D systems, such as graphene and two-dimensional electron gases, and can be extended to opaque bulk materials with at surfaces.