Mechanism of ferromagnetism in(Fe,Co)-codoped 4H-SiC from density functional theory

First-principles calculations are performed to investigate the electronic structures and magnetic properties of(Fe,Co)-codoped 4H-SiC using the generalized gradient approximation plus Hubbard U method.We find that 4H-SiC doped with an isolated Fe atom and an isolated Co atom produces a total magnetic moment of 5.98μB and 6.00μB respectively.We estimate TC of about 263.1 K for the(Fe,Co)-codoped 4H-SiC system.We study ferromagnetic and antiferromagnetic coupling in(Fe,Co)-codoped 4H-SiC.Ferromagnetic behavior is observed.The strong ferromagnetic couplings between local magnetic moments can be attributed to p–d hybridization between Fe,Co and neighboring C.However,the(Fe,Co,V(Si))-codoped 4H-SiC system shows antiferromagnetic coupling when an Si vacancy is introduced in the same 4H-SiC supercell.The results may be helpful for further study on transition metal-codoped systems.