The bias-controlled giant magnetoimpedance effect caused by the interface states in a metal-insulator-semiconductor structure with the Schottky barrier

We demonstrate that ferromagnetic metal/insulator/semiconductor hybrid structures represent a class of materials with the giant magnetoimpedance effect. In a metal-insulator-semiconductor diode with the Schottky barrier fabricated on the basis of the Fe/SiO2/n-Si structure, a drastic change in the impedance in an applied magnetic field was found. The maximum value of this effect was observed at temperatures of 10–30 K in the frequency range of 10 Hz–1 MHz where the ac magnetoresistance and magnetoreactance ratios exceeded 300% and 600%, respectively. In the low-frequency region (<1 kHz), these ratios could be controlled in wide range by applying bias to the device. The main contribution to the impedance when measured at temperatures corresponding to the strongest magnetic-field sensitivity comes from the interface states localized near the SiO2/n-Si interface and the processes of their recharging in an applied ac voltage. The applied magnetic field changes the energy structure of the interface states, thus affecting the processes of the charging dynamics.