Hole-mediated electric field tunable high Curie temperature in Mn-doped wurtzite ZnO nanowires

The hole-mediated Curie temperature in Mn-doped wurtzite ZnO nanowires is investigated using the k∙p method and mean field model. The Curie temperature TC as a function of the hole density has many peaks for small Mn concentration (xeff) due to the density of states of one-dimensional quantum wires. The peaks of TC are merged by the carriers’ thermal distribution when xeff is large. High Curie temperature TC>400K is found in (Zn,Mn)O nanowires. A transverse electric field changes the Curie temperature a lot. (Zn,Mn)O nanowires can be tuned from ferromagnetic to paramagnetic by a transverse electric field at room temperature.