Transport and magnetic properties of ZnCo2O4/Si heterostructures grown by radio frequency magnetron sputtering

We report a growth of ZnCo2O4/Si heterostructures by using radio frequency magnetron sputtering (RFMS) method, and characterizations of their transport and magnetic properties. It is found that the ZnCo2O4/Si heterostructures exhibit a good rectifying behavior at four measured temperatures of 100 K, 150 K, 200 K, and 290 K. The energy band structure reveals that the electron is the mainly contributing factor to the current of the ZnCo2O4/Si heterostructures. The transport behaviors of these heterostructures can be qualitatively explained by diffusion or recombination in the space charge region at low voltages ranging from 0.16 V to 0.3 V, and the space-charge-limited current conduction mechanism plays a main role when the voltage is higher than 0.3 V. The magnetic measurements of the ZnCo2O4/Si heterostructures indicate a strong ferromagnetic behavior at oxygen pressures ranging from 1.333 Pa to 6.665 Pa. It is believed that this work would open perspectives for ZnCo2O4/Si heterostructure-based devices. (C) 2014 Elsevier B.V. All rights reserved.