Investigação das propriedades magnetoelásticas da ferrita de níquel : análise teórico-experimental
Resumen
In this dissertation, we investigate the magnetoelastic properties of nickel ferrite compared
to the pure metal nickel, either by ab-initio calculation or through experiments using the
capactive cell technique. The first step of our approach is to establish the convergence
criteria on density functional theory (DFT). This also required us to benchmark our
method by using other materials such as pure Fe, Co and diamond. The first step of
our study is to explore not only the approach of DFT but also its capacity to describe
other properties. Since all the electronic structures of theses material have been suitably
reported, the second step of our calculation demonstrates how close to the experimental
data DFT may result the elastic constants. The results has shown reasonably error to the
actual values. On the third moment, our investigation resides to find the magnetostriction
coefficient through DFT, which met in accordance with the experiments we carried out
using the capacitance technique.