Dielectric response of (K_0.5Na_0.5)NbO₃/CoFe₂O₄/(K_0.5Na_0.5)NbO₃ magnetoelectric sandwich films

ABSTRACT

The sandwich magnetoelectric (K_0.5Na_0.5)NbO₃/CoFe₂O₄/(K_0.5Na_0.5)NbO₃ films have been fabricated on Ni–5 at.%W RABiTS tape by pulsed laser deposition. The dielectric properties of the films have been investigated. The dielectric tunability of the sandwich films increases initially and then decreases with increasing the bias field. It is suggested that the peak behavior originates from the interfacial polarization, trapping and locking mechanisms. The abnormal dielectric tunability not only has some new physical meanings, but also has potential practical applications in detectors, sensors and so on.

KEYWORDS:

• Dielectric constant
• deposition
• thin films
• tunability

Acknowledgments

This work is supported by the National Natural Science Foundation of China (NSFC Nos. 11547048, 11472259 and 51271172) and Zhejiang Provincial Natural Science Foundation of China (No. LR13A020002).