Calculation of Electronic Structures and Magnetic Properties of α-Quartz SiO2 with and without Transition Metal Elements

Abstract

Electronic structures and magnetic properties of pure α-quartz SiO2 and doped α-quartz Si1-xMx O2 , where M represents the transition metals V, Cr and Mn, are calculated using the Gaussian98 program with the Hartree-Fock (HF) and Density Functional Theory (DFT) methods. In this calculation Si18O26H32 and Si17MO26H32 represent pure and doped α-quartz SiO2 respectively. The total energy calculated by DFT is found to be smaller than that calculated by HF and the lowest is found in Si17MnO26H32. The results show that the energy gaps of Si18O26H32 calculated by HF and DFT methods are 15.766 eV and 7.560 eV respectively. The energy gaps of doped α-quartz SiO2 calculated by both methods, are found to reduce and the narrowest one is found in Si17CrO26H32. The calculations of the total dipole moments show that these values are higher in doped α-quartz SiO2 than in pure α-quartz SiO2 , while the highest is found in Si17MnO26H32.