Nitrogen embedded ZnO:N films prepared by pulsed laser deposition exhibit significant ferromagnetism. The nitrogen ions contained in ZnO confirmed by Secondary Ion Microscopic Spectrum and Raman experiments and the embedded nitrogen ions can be regarded as defects. According to the experiment results, a mechanism is proposed based on one of the electrons in the completely filled dorbits of Zn that compensates the dangling bonds of nitrogen ions and leads to a net spin of one half in the Zn orbits. These one half spins strongly correlate with localized electrons that are captured by defects to form ferromagnetism. Eventually, the magnetism of nitrogen embedded ZnO:N films could be described by a bound magnetic polaron model.

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Observation of the room temperature ͑RT͒ anomalous Hall effect ͑AHE͒ and ferromagnetism in semiconducting like ͑carrier concentration ϳ10 19 cm −3 ͒ Co-doped ZnO samples is reported. These small AHE signals match quantitatively with the magnetic hysteresis and can be correspondent to the intrinsic diluted magnetic oxide ͑DMO͒ effect with spin polarized carriers. The contribution to the DMO effect depends on the types of carriers and how they incorporated into the electric conduction, magnetic coupling, and the coupling between them. These findings can provide useful information in the study of the origin of RT ferromagnetism in ZnO-based DMO and for further application in spintronics.

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Exchange bias and enhanced coercivity in phase separated La0.45Sr0.55MnO3 and Pr0.55(Ca0.65S0.35)