Abstract:
TheStructural andelectronicProperties of BismuthFerrite(BiFeO3)wasinvestigated
with density functional theory (DFT) using Quantum Espresso package. Our study
was based on Density Functional Theory (DFT) with the Perdew-Burke-Ernzerhof
(PBE) exchange-correlation functional, Vanderbilt (Norm-conserving) pseudo po
tentials and the plane wavebasissetimplementedintheQuantum-ESPRESSOpack
age. The calculation of the total minimum energy and the total minimum force of
BiFeO3 wascalculatedasafunctionofcutoffenergyandK-pointssampling. Thetotal
minimumenergy per cell is monotonically decreasing with increasing cutoff energy
due to variational principle. However, this trend can not be predicted from increas
ing the k-points sampling. The energy cut-off (90 Ry) and k-point grid (5x5x5) valued
from total minimum energy convergence test. The computational value of the equi
librium lattice constant is 10.0 Bohr. This result is nearly in good agreement with
experimental value is 10.2569 Bohr, with the experimental result of percentage error
of 2.4%. Inadditiontothisthebandstructureandtotaldensityofstatearecalculated.
Fromthebandstructure it is observed that the band gap value is under estimated as
compared to the experimental band gap value and the band gap of bismuth ferrite
(BiFeO3) is 1.68 eV.
