Indexed by:Journal paper First Author:徐刚 Correspondence Author:方忠 Co-author:Gang Xu, Wenmei Ming, Yugui Yao, Xi Dai, S-C Zhang, Zhong Fang Journal:Europhysics Letters Included Journals:SCI、EI Discipline:Science First-Level Discipline:Physics Document Type:J Volume:82 Issue:6 Page Number:67002 Date of Publication:2008-06-03 Abstract:By first-principles calculations, we present a doping-dependent phase diagram of the LaOMAs (M= V–Cu) family. It is characterized as a antiferromagnetic semiconductor around the LaOMnAs side and as a ferromagnetic metal around LaOCoAs. Both LaOFeAs and LaONiAs, where superconductivity were discovered, are located at the borderline of magnetic phases. An extensive Fermi surface analysis suggests that the observed superconductivity is of electron type in its origin. We discuss possible pairing mechanisms in the context of competing ferromagnetic phases found in this work.