Electronic and magnetic properties of the CuO4- and Co2CuO10-complexes in diluted magnetic semiconductors and transition metal oxides

Understanding the nature of magnetism in diluted magnetic semiconductors (DMSs) and doped transition metal oxides (TMOs) requires questioning the role oflocal or the long range aspect of the magnetic coupling among the dopants in these materials. A possible clue seems to emerge from an examination of recent and previous reports suggesting that, despite a holistic response of a DMS- or TMO-host to its magnetic doping, local processes underlay the establishment of magnetism. In the present work, we investigate this problem by examining in detail two doped systems, namely Zn(Cu)O and Zn(Co2Cu)O while focusing on the electronic and magnetic properties of the magnetic complexes CuO4 and Co2CuO10 which are formed, respectively, in Zn(Cu)O and Zn(Co2Cu)O using ab initio and tight-binding calculations. Our results demonstrate that the local aspects play a predominant role in the establishment of the magnetic coupling.