Electronic structure and magnetism of Eu-doped GaN: first-principles study based on LDA+U

Electronic and magnetic properties of the rare-earth-doped III-nitride semiconductor Ga1-xEuxN (x = 0.0625) is studied with the full potential (linearized) augmented plane wave method plus the local orbitals method, where we have explored the electronic and magnetic properties of the ferromagnetic Ga1-xEuxN in the zinc-blende phase. The existence of Eu 4f orbitals has demonstrated that the common local density approximation leads to quantitatively and qualitatively wrong results, while the LDA + U method performs much better. In this paper we present only the results related to the LDA + U method. It is found from the calculation of density of states that the Eu f orbitals spin-polarize the host system and they are predominant in this diluted magnetic semiconductor. The magnetic description is achieved by the calculation of spin densities difference contours and the magnetic moment.