Acoplamento spin-fônon nos multiferróicos CuX2 (X = Br, Cl)

• Ano de defesa: 2019
• Autor(a) principal: Medeiros, Fabio Eduardo de Oliveira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Materiais Multiferroicos; Espectroscopia Raman; Acoplamento spin-fônon; Brometo de cobre; Cloreto de cobre
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/40298

With the growth of interest in muitrferroic materials in the last years, many techniques have been used in their base study in order to provide more knowledge about the operation of their ferrous characteristics, being them ferroelectricity, ferro/antiferromagnetism and ferroelasticity. In the present work the Raman scattering spectroscopy technique was applied in order to observe the behavior of the active Raman vibrational modes of the multiferroic copper chloride (CuCl2) and copper bromide (CuBr2) subjected to low temperatures and the possible existence of the spin-phonon coupling present in them. On the other hand, a study using Ramam spectroscopy and simultaneous thermal analysis of thermogravimetry (TG) and differential scanning calorimetry (DCS) was carried out by monitoring the transition of copper chloride from its dihydrated and orthorhombic phase (CuCl2⋅2H2O) for its anhydrous and monoclinic phase (CuCl2) when subjected to heating dehydration.