Banca de QUALIFICAÇÃO: MAYCON ERICLES MACEDO BARROS

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE: MAYCON ERICLES MACEDO BARROS
DATA: 15/08/2025
HORA: 14:00
LOCAL: Auditório do Departamento de Física
TÍTULO: Spin-dependent electronic properties of bilayer ɑ- graphyne zigzag nanoribbons: a density functional theory study
PALAVRAS-CHAVES: ɑ-graphyne, bilayer, nanoribbons, spin-polarized
PÁGINAS: 43
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Física
RESUMO:

Graphyne-based nanostructures have attracted growing interest
due to their unique electronic and mechanical properties arising from a
combination of and 2 hybridized carbon atoms. Recent advances have sp sp
enabled the synthesis of various graphyne members, including few-layer
films, quantum dots, and nanoribbons, opening new possibilities for
nanoscale applications. In this work, we present a first-principles
investigation of the spin-dependent structural and electronic properties of
bilayer zigzag nanoribbons derived from the ɑ-graphyne lattice. Four stacking
arrangements — AA, Ab, AB-ɑ, and AB-β, were considered, all resulting in
non-planar geometries. Our results reveal that the electronic behavior of the
ribbons is highly sensitive to both the stacking configuration and ribbon
width, exhibiting metallic, semiconducting, and half-metallic characteristics.
We find that spin-polarized (SP) states emerge in the AB-ɑ and AB-β stackings,
where different interlayer and intralayer magnetic alignments lead to
distinct electronic behaviors. Notably, the non-planar geometry does not
suppress magnetization, in contrast to bilayer graphene-based ribbons.
Additionally, we show that applying an external transverse electric field can
effectively modulate the band structure of the ribbons, inducing a
semiconductor-to-metal transition. These findings provide key insights into
the tunability of spin-dependent electronic properties in ɑ-graphyne bilayer
systems, with potential implications for spintronic and nanoelectronic device
applications.

MEMBROS DA BANCA:
Interno - 1548848 - EDUARDO COSTA GIRAO
Externo ao Programa - 1257306 - JOSÉ FERREIRA DA SILVA NETO
Presidente - 1250015 - PALOMA VIEIRA DA SILVA
Interno - 1340442 - RAMON SAMPAIO FERREIRA