Enhance ferromagnetism by stabilizing the cation vacancies in GaN Zhen-kun Tang, Deng-Yu Zhang, Li-Ming Tang, Ling-Ling Wang and Ke-Qiu Chen Eur. Phys. J. B, 86 6 (2013) 284 Published online: 24 June 2013 DOI: 10.1140/epjb/e2013-30474-0