Odd temperature-dependent ferromagnetism in nitrogen-doped ZnTe
Shih-Jye Sun1*, Hsiung Chou2, Lech. T. Baczewski3
1Applied physics, National University of Kaohsiung, Kaohsiung, Taiwan
2Physics, National Sun Yat-sen University, Kaohsiung, Taiwan
3Magnetism, Polish Academy of Sciences, Warsaw, Poland
* Presenter:Shih-Jye Sun, email:sjs@nuk.edu.tw
The observation of ferromagnetism in nonmagnetic ion-doped metal oxides has stimulated the theoretical investigations to explain ferromagnetism's origin. This work demonstrates experimentally by a direct comparison of hysteresis loops for undoped and N doped nanowires that the ferromagnetism appears in the nitrogen-doped ZnTe (ZnTe:N) nanowires similarly to the case of the nitrogen-doped ZnO (ZnO:N) thin films. In particular, the negative temperature-dependent ferromagnetism (NTDF) is observed in the ZnTe:N nanowires. A model is proposed to interpret the experimental results assuming that the ferromagnetism and NTDF in ZnTe:N nanowires are due to the thermally excited electrons from the conduction band to the nitrogen impurity states as well as the Coulomb excitations induced in these states.

Keywords: Ferromagnetic model, Ferromagnetic ZnTe nanowires, Coulomb excitation, Nitrogen-doped ZnTe nanowires