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AlN films were prepared by medium-frequency reactive magnetron sputtering and subsequently implanted with 200 keV Mn[sup +] ions with a dose of 5×10[sup 16] cm[sup -2]. The properties of Mn[sup +]-implanted AlN films were investigated by optical and magnetic measurements. Cathodoluminescence (CL) measurements showed a peak at 2.07 eV in AlN and a broad luminescence band around 2.0–3.4 eV in the implanted samples. Fitting of the CL data reveals three peaks, among which the main peak is located at 2.6 eV and attributed to a donor-to-Mn[sup 2+] transition. The magnetic measurement showed a transition temperature of 100 K in the implanted AlN annealed at 500 °C for 30 min. Clear ferromagnetic hysteresis was observed at 77 K, with a coercive field of 212.7 Oe. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We propose a spin selector of ferroelectric triple barrier resonant tunneling diode with diluted magnetic quantum wells. Spin transport properties of this spin selector are investigated by nonequilibrium Green’s function method. Results show the oscillation of spin polarization of current occurred at low bias voltage due to a transmission resonant peak splitting into subpeaks. By reversing the electric dipole direction of ferroelectric barriers, the spin direction of polarized current is reversed simultaneously at a fixed bias voltage. This implies that the spin direction of injected current can be selected through this spin selector without changing the applied magnetic field. [ABSTRACT FROM AUTHOR]

The spin transport through a resonant tunneling diode with a ferroelectric quantum well is studied by nonequilibrium Green’s function method. The results show that the spin polarization can be switched by changing the dipole direction of the ferroelectric quantum well in a resonant tunneling diode. At a special bias, the authors can get highly spin polarized current or evenly spin mixed current depending on the dipole direction. [ABSTRACT FROM AUTHOR]

Achievement of a spin polarization without magnetic field through a GaMnN based ferromagnetic resonant tunneling diode (RTD) is proposed theoretically. The influences of the temperature and structure on the spin polarization current and differential conductance have been investigated. The clear spin splitting current can be observed in an optimal RTD structure without magnetic field even though the splitting energy of the ferromagnetic barrier is very small. Large spin polarization can be obtained and the polarization orientation can be varied by an applied bias voltage without external magnetic field. [ABSTRACT FROM AUTHOR]