The effects of N vacancies upon transition metal (Cr, Mn, Fe, Co, Ni, and Cu)

doped GaN were studied at the level of the local spin density approximation and

LSDA+U (Coulomb interaction). The calculations showed that the N vacancy was

favorably placed near to a transition metal ion and the interaction between the

transition metal ion and the N vacancy was insensitive to distances exceeding 3.3Å.

Furthermore, it was found that the existing N vacancies altered the magnetic

moments of the doped GaN, where the magnetic moments increased for Cr or Mn

doped GaN, and decreased for Fe, Co, Ni, or Cu doped GaN. This result could be

interpreted well by the Hund's multiplicity rules. However, it was found that the

magnetic moments of doped GaN with N vacancies were insensitive to the

distances between N vacancies and the doped transition metal ions. The results

obtained were useful in elucidating the effects of N vacancies upon the magnetic

properties of transition metal doped GaN.

Effects of Nitrogen Vacancies on Transition-Metal-Doped GaN: an Ab Initio Study.

B.Xu, B.C.Pan: Journal of Applied Physics, 2009, 105[10], 103710