Electrical Charging Effect in Room-Temperature-Ferromagnetic ZnMnO:N Nanocrystals Embedded into a SiO2 Layer

The Zn0.9₃Mn0.07O:N nanocrystals embedded into a SiO₂ layer were formed by using the thermal-nucleation process with a SiO₂/(Zn$_{0.93}$Mn$_{0.07}$)O:N/SiO₂ ultrathin multilayer. The formed (Zn0.9₃Mn0.07O:N nanocrystals showed clear ferromagnetism with Mr ~ 6.54 x 10-6 emu/g and Hc ~ 77.78 Oe, which persisted up to 350 K. The observed high-Tc ferromagnetism is considered as originating from the enhancement of ferromagnetic coupling due to increases in both the carrier-confinement effect and the manganese-disorder effect attributed to the nucleation of (Zn0.₃Mn0.07)O:N nanocrystallites. The memory capacitor fabricated using the (Zn0.9₃Mn0.07)O:N nanocrystals clearly showed an electrical charging effect with △VFB ~ 0.63 V and the spin tunneling diode fabricated using the room-temperature-ferromagnetic (Zn0.9₃Mn0.0)O:N nanocrystals revealed the sequential tunnel transport behaviors of spin-polarized carriers. These results suggest that (Zn0.9₃Mn0.07)O:N nanocrystals can be used for spin-functional memory devices. KCI Citation Count: 3