Banca de DEFESA: FABIO JUVENCIO RAMALHO COSTA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : FABIO JUVENCIO RAMALHO COSTA
DATA : 06/08/2020
HORA: 14:00
LOCAL: ConferênciaWeb https://conferenciaweb.rnp.br/webconf/ppgfisdefesas
TÍTULO:

Theoretical Investigation of Superconductivity in Diamond: Doping and Pressure Effects

PALAVRAS-CHAVES:

Superconductivity; Doped-diamond; Pressure.

PÁGINAS: 145
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Física
RESUMO:

The electronic structure, lattice dynamics and electron-phonon coupling of pure, boron and nitrogen-doped diamond carbon were investigated, within the generalised-gradient and virtual crystal approximations. To examine the influence of impurity content and pressure on the superconductivity of these systems, the electron-phonon coupling constant (λ) and the critical temperature (Tc) were calculated, within concentration from 0-15% and pressures from 0-90 GPa. Regarding the boron-doped diamond, the calculations indicated that this system’s electron-phonon coupling strongly relates to the optical phonon modes, and the estimated critical temperatures matched previous theoretical and experimental results. Regarding the nitrogen-doped case, it was observed that both λ and Tc were
larger than those obtained for the hole-doped case. The most distinguishing feature of this system was it’s rising acoustic contribution to the electron-phonon coupling, which led to significant values for λ and Tc. All scenarios presented a decreasing critical temperature with increasing pressure. In opposition to the other cases, the C0.85N0.15 system exhibited a positive dependence between critical temperature and pressure, leading to an estimate of the superconducting transition to happen at 121.92 K, at 20 GPa.

MEMBROS DA BANCA:
Externo à Instituição - ANDREIA LUISA DA ROSA
Interno - 287748 - FERNANDO DE BRITO MOTA
Interno - 1650037 - JAILTON SOUZA DE ALMEIDA