Stable ferromagnetism in p-type carbon-doped ZnO nanoneedles

Abstract

The authors report the synthesis and magnetic properties of carbon-doped ZnO (ZnO:C) nanoneedles. A saturated magnetic moment of 2.16 emu/cm³ was found in the ZnO:C nanoneedles. The samples showed anomalous Hall effect and p-type conduction with a hole concentration of 1.8 X 10¹⁸cm⁻³. The ferromagnetism in the ZnO:C nanoneedles could be attributed to C substitution on the O site which introduces hole, so the p-p interaction leads to the strong spin interaction between the C atoms and carriers. It was found that the ferromagnetism and p-type conduction in the ZnO:C nanoneedles were stable in ambient air over a period of 1 year and annealing temperature of up to 100 °C.