Abstracts Book - IMRC 2018

• SA1-P027
MORPHOLOGY AND MICROSTRUCTURE EFFECTS ON THE
MAGNETOTRANSPORT CHARACTERISTICS OF CARBON
NANOWALLS OBTAINED IN DIFFERENT PARAMETERS OF
SYNTHESIS BY PECVD
Mijaela Acosta Gentoiu 1 , Marius Volmer 2 , Sorin Vizireanu 3 , Stefan Antohe 4 , Gheorghe Dinescu 3 ,
Rene Betancourt Riera 5 , Raul Riera Aroche 1
1 Universidad de Sonora, Departamento de Investigación en Física, Mexico. 2 Transilvania
University, Transilvania University, Rumania. 3 National Institute for Lasers, Plasma and
Radiation Physics, National Institute for Lasers, Plasma and Radiation Physics, Rumania.
4
University of Bucharest, Faculty of Physics, Rumania. 5 Instituto Tecnológico de Sonora,
Instituto Tecnológico de Hermosillo, Mexico.
We report a comparative study of electrical and magnetotransport properties of
carbon nanowalls (CNWs) with different morphologies, internal microstructure
and size (thickness as well as lateral) measured in a magnetic field (up to 7 T)
over a temperature range (15-30 K). The CNWs are grown by a plasma enhanced
CVD process on gold-chrome electrodes supported by a silicon oxide varying
deposition temperature, Ar flux and time. Scanning electron microscopy,
transmission electron microscopy, X-ray photoelectron and Raman
spectroscopy were used to substantiate the structural differences in the
samples. It is shown a significant difference in the resistance–magnetic field
between two samples with different morphology, defects and microstructure.
Sample 1 exhibited negative values of magnetoresistance whereas the second
one presented positive values with a quadratic field dependence. These
behaviours are explained in terms of the effect of electron scattering at reactive
edges, defects, crystalline regions separated by interfaces and dense
boundaries. Also, we found changes in the resistance upon thickness of the walls
sugesting that their internal microstructure is important. Our results propitiate
a way towards the use of vertical graphene or CNWs in magnetoelectronic
nanodevices with magnetic properties tuneable through their morphology and
microstructure.
Keywords: nanowall, graphene, magnetotransport
Presenting authors email: macostagen@gmail.com