Crossing points in the electronic band structure of vanadium oxide

• Main Authors: Zabidi, Noriza A., Kassim, Hasan A., Shrivastava, Keshav N.
• Format: Conference or Workshop Item
• Language: English
• Published: 2010
• Subjects: QC Physics
• Online Access: http://eprints.um.edu.my/11258/1/Crossing_points_in_the_electronic_band_structure_of_vanadium_oxide.pdf; http://eprints.um.edu.my/11258/

The electronic band structures of several models of vanadium oxide are calculated. In the models 1-3, every vanadium atom is connected to 4 oxygen atoms and every oxygen atom is connected to 4 vanadium atoms. In model 1, a=b=c 2.3574 A; in model 2, a= 4.7148 A, b= 2.3574 A and c= 2.3574 A; and in model 3, a= 4.7148 A, b= 2.3574 A and c= 4.7148 A. In the models 4-6, every vanadium atom is connected to 4 oxygen atoms and every oxygen atom is connected to 2 vanadium atoms. In model 4, a=b= 4.551 A and c= 2.851 A; in model 5, a=b=c= 3.468 A; and in model 6, a=b=c= 3.171 A. We have searched for a crossing point in the band structure of all the models. In model 1 there is a point at which five bands appear to meet but the gap is 7.3 meV. In model 2 there is a crossing point between G and F points and there is a point between F and Q with the gap > 3.6608 meV. In model 3, the gap is very small, - 10-5 eV. In model 4, the gap is 5.25 meV. In model 5, the gap between Z and G points is 2.035 meV, and in model 6 the gap at Z point is 4.3175 meV. The crossing point in model 2 looks like one line is bent so that the supersymmetry is broken. When pseudopotentials are replaced by a full band calculation, the crossing point changes into a gap of2.72 x 10-4 eV.