The voltage- and time-dependence of the tunneling currents in polysilicon–oxide–nitride–oxide semiconductor structures have been investigated. Electron and hole contributions were separated using a shallow junction technique. The standard tunneling model for charge injection was successfully applied to describe the observed threshold voltage shifts. For both positive and negative gate voltages, the time-dependence of the current density through the tunneling oxide is given by a simple analytical equation. This equation is characterized by an initial time constant and an asymptotic t−1-dependence. At large programming times the current density follows the t−1-dependence, independent of the tunneling oxide thickness and applied voltage. Under positive polarity (write) electrons are injected from the substrate. Under negative polarity (erase) and previous injection electron back-tunneling rather than hole injection is dominant at the beginning of erasing. At the end of erasing, steady-state conduction can be dominated either by electrons or holes, depending on the applied voltage.

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Magnetic and electrical measurements are reported on single crystals of CdCr2Se4. The measurements include ferromagnetic resonance linewidth and magnetic moment vs temperature, magnetic anisotropy constant K1 and g-factor at 4.2°K, and the sign of the Seebeck coefficient at 300°K. A theoretical calculation of K1 at 4.2°K is also presented.

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