Compostos diamondol tipo B-C-N: estabilidade e propriedades eletrônicas

• Ano de defesa: 2023
• Autor(a) principal: Pinto, Allan Kleyton Muniz
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal da Paraíba; Brasil; Física; Programa de Pós-Graduação em Física; UFPB
• Palavras-chave em Português: Física da matéria condensada; Estrutura eletrônica; Teoria do funcional da densidade; Diamondol; Bonitrol; Condensed matter physics; Electronic structure; Density Functional Theory (DFT); CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA
• Link de acesso: https://repositorio.ufpb.br/jspui/handle/123456789/27352

Graphene isanallotropeofcarbonwithpropertiesofgreatphysicalinterest;itwas the firsttwo-dimensionalmaterialtobeisolated,whichmotivatedtheinvestigationofnew low-dimensionalmaterials.Applyinghighpressureunderthegraphenebilayerrevealed atomic rearrangementinadiamond-likestructure.Thissystem,calleddiamondol,istwo- dimensional material(2D)withthecarbonatomsofoneofthemonolayersbondingwith a hydroxyl.Diamondolcanbehaveasasemiconductororaninsulator—dependingon the spincomponent—andisferromagneticwithamagneticmomentof1 μB perunitcell. Analogously,bonitrol,whichismadeupofboronandnitrogeninsteadofcarbon,hasa metallic andferromagneticcharacter.Thisraisesthequestionofthepossibilityofmixing B−C−N compoundssimilartodiamondolinanattempttomodifytheelectronicbehavior. Tothisend,weperformedfirst-principlecalculationsofthestructural,vibrational,magne- tic andelectronicstructurepropertiesofdiamondol-likecompounds,replacingboronand nitrogen atomswithcarbonatoms.Ourresultsshowedthattheformationenergyincreases with thenumberofcarbonatoms,withbonitrolhavingthelowestenergy(-0.52eV/atom) and diamondolhavingthehighest(0.18eV/atom).Inadditiontobonitrol,wefoundeleven other caseswithnegativeformationenergy,indicatinganexothermicprocess.Weverified the mechanicalstabilityviaphonondispersionofthecaseswithnegativeformationenergy, according tothecarbonconcentration.Inallthesecases,weobserveonlypositivefrequen- cies, demonstratingthatoursystemsaremechanicallystable.Themagneticandelectronic characterizationshowedarichphenomenology,includingmagneticmomentsandelectronic behaviorrangingfromsemiconductortometallicandhalf-metallic.