Banca de DEFESA: PABLO MENEZES AMORIM

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : PABLO MENEZES AMORIM
DATE: 16/01/2023
TIME: 09:00
LOCAL: Plataforma da conferência WEB - RNP
TITLE:

Transformed profile of average height: analysis of exponents of scale and its connection with the morphology that results from computer simulation of force microscopy electrostatic.

KEY WORDS:

computer simulation of microscopy; electrostatic force.

PAGES: 90
BIG AREA: Ciências Exatas e da Terra
AREA: Física
SUMMARY:

Surface growth is an important out-of-equilibrium phenomenon and has several
technological applications, such as the thin film manufacturing process. Some
information about this phenomenon can be obtained through computer
simulations using lattice models, via the Kinetic Monte Carlo method. In this
dissertation, results of computer simulations will be exposed for discrete models
said to belong to the universality class of the KPZ (Kadar-Parisi-Zhang) and
VLDS (Villain-Lai-Das Sarma) equations. Interfaces that show wrinkling can show
certain statistical quantities that are invariant under scaling transformations,
defining scaling exponents. However, the scale exponents are well defined in the
hydrodynamic limit, because of this, obtaining these exponents is subject to time
effects and finite size. In addition, the existence of an intrinsic roughness that
modifies the Family-Vicsek (FV) scale ratio is reported in the literature, which is
one of the origins of scale corrections for certain models. In order to circumvent
the action of these effects in obtaining the exponents that characterize the scale,
scale correction methods were developed, quoting the extrapolation method
proposed by Aarão Reis. In the present work, we propose a technique applied to
lattice models, which helps to obtain the local roughness exponent. The
technique called TMHP (Transformed Mean Height Profile), consists of dividing
the discrete irregular profile into several bins (compartments of the same size),
to produce a transformed profile of average heights. The profile generated by the
TMHP technique was able to attenuate the stochastic fluctuations of heights in
the regions of valleys and peaks, generating a smoother profile and reducing the
effect of intrinsic roughness on the scale. Furthermore, for compartment sizes
smaller than the correlation length of the original profile, the profile generated by
the technique is equivalent to the original profile, with regard to the scale
exponents. A feature of the TMHP technique is the existence of an optimal bin,
which is the bin size capable of providing a better correction for the local
roughness exponent. In the case of discrete models belonging to the KPZ class,
the results show that the global growth exponent remains unchanged for profiles
generated by TMHP through the optimal bin. However, for bin sizes that exceed
the original profile correlation length, the growth exponent reported by the TMHP
technique is consistent with that of an uncorrelated growth. Finally, it will be
discussed under what conditions there is a connection between the transformed
profile and the one reported through computer simulations of a specific type of
AFM (Atomic Force Microscopy), called electrostatic probe microscopy.

COMMITTEE MEMBERS:
Externo à Instituição - FABIO DAVID ALVES AARAO REIS - UFF
Externo à Instituição - SUKARNO OLAVO FERREIRA - UFV
Presidente - 1876752 - THIAGO ALBUQUERQUE DE ASSIS