30 research outputs found
Vector magnetometry using silicon vacancies in 4H-SiC at ambient conditions
Point defects in solids promise precise measurements of various quantities.
Especially magnetic field sensing using the spin of point defects has been of
great interest recently. When optical readout of spin states is used, point
defects achieve optical magnetic imaging with high spatial resolution at
ambient conditions. Here, we demonstrate that genuine optical vector
magnetometry can be realized using the silicon vacancy in SiC, which has an
uncommon S=3/2 spin. To this end, we develop and experimentally test sensing
protocols based on a reference field approach combined with multi frequency
spin excitation. Our works suggest that the silicon vacancy in an
industry-friendly platform, SiC, has potential for various magnetometry
applications at ambient conditions
Optical properties and Zeeman spectroscopy of niobium in silicon carbide
The optical signature of niobium in the low-temperature photoluminescence spectra of three common polytypes of SiC (4H, 6H, and 15R) is observed and confirms the previously suggested concept that Nb occupies preferably the Si-C divacancy with both Si and C at hexagonal sites. Using this concept we propose a model considering a Nb-bound exciton, the recombination of which is responsible for the observed luminescence. The exciton energy is estimated using first-principles calculation and the result is in very good agreement with the experimentally observed photon energy in 4H SiC at low temperature. The appearance of six Nb-related lines in the spectra of the hexagonal 4H and 6H polytypes at higher temperatures is tentatively explained on the grounds of the proposed model and the concept that the Nb center can exist in both C1h and C3v symmetries. The Zeeman splitting of the photoluminescence lines is also recorded in two different experimental geometries and the results are compared with theory based on phenomenological Hamiltonians. Our results show that Nb occupying the divacancy at the hexagonal site in the studied SiC polytypes behaves like a deep acceptor
Использование принципа клиентоориентированности при формировании стратегии развития предприятий
Материалы межвуз. науч. конф. студентов, магистрантов и аспирантов, Гомель, 15 мая 2008 г