A study was made of the role which was played by defects, in the magnetic properties of C materials, using first-principles density functional methods. It was shown that, while the total magnetization decreased for both diamond and graphite with increasing vacancy density, the magnetization decreased more rapidly for graphitic structures. The presence of N near to a vacancy was shown to produce larger macroscopic magnetic signals as compared to a stand-alone C vacancy. The results indicated the possibility of tuning magnetization in C by controlled defect generation and doping.

First-Principles Study of Defect-Induced Magnetism in Carbon. Y.Zhang, S.Talapatra, S.Kar, R.Vajtai, S.K.Nayak, P.M.Ajayan: Physical Review Letters, 2007, 99[10], 107201