Role of Al atom on structural and magnetic properties of β-SiC:Cr

The electronic structure, magnetic properties and also the bonding mechanism of the pure SiC and compounds SiC:Cr and SiC:Cr:Al have been studied using the Quantum SPRESSO Software within the density-functional theory (DFT). β-SiC, which is a nonmagnetic semiconductor, has more applications in industry. For the magnetic property, it is alloyed with transition metal. One of the transition metal is chromium. The calculations showed that its alloy at both Si site and C site (SiC:Cr) changes the physical properties of the host material and contributes in the molecular bond. It is seen that if the Al atom was doped in the compounds, SiC:Cr will produce hole carriers and the magnetic properties will thus increase to the considerable values due to the mediation effect. The magnetic property will create the up and down spin band gap to filter carriers. The charge density distribution illustrates that the Al atom has the atomic behavior in the compounds Sic:Cr:Al and does not contribute in the molecular bond. For comparison, the calculations were performed for the pure β-SiC.