First Principles Studies Of 2D Magnets

Sammanfattning

The aim of this project is to examine the electric and magneticproperties of three monolayer chromium trihalides when doped withdifferent transitions metals, that is CrXY_6, where X=(Mn,Fe,Co,Ni,V)and Y=(Cl,Br,I). The calculations were made using the software programQuantum Espresso that used density functional theory to solveSchrödinger’s equation. The first step of the calculations was to optimize the atomic positionsand the lattice parameters to find the ground state energy of thecompounds. The magnetic configuration was also examined to find thefavorable configuration. With the optimized values for each compound,the band structure, density of states and the projected density ofstates was calculated. The results confirmed the ferromagnetic behaviorof non-doped compounds, however for some of the doped compounds themagnetic configurations changed to anti-ferromagnetic. Most of thecompounds retained their semiconductor properties when doped and had aband gap near the fermi-energy, while other changed to metallic or halfmetallic and had available electron states at fermi-energy.