Ferroelectricity in hexagonal YFeO3 film at room temperature**Project supported by the National Natural Science Foundation of China (Grant Nos. 61471301, 61078057, 51202195, and 511172183), the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20126102110045), and the NPU Foundation for Fundamental Research (Grant Nos. JC201155, JC201271, and JC20120246).

Abstract

In this paper we report the leakage current, ferroelectric and piezoelectric properties of the YFeO3 film with hexagonal structure, which was fabricated on Si(111) substrate by a simple sol-gel method. The leakage current test shows good characteristics as the leakage current density is 5.4×10−6 A/cm2 under 5 V. The dominant leakage mechanism is found to be an Ohmic behavior at low electric field and space-charge-limited conduction at high electric field region. The P–E measurements show ferroelectric hysteresis loops with small remnant polarization and coercive field at room temperature. The distinct and switchable domain structures on the nanometer scale are observed by piezoresponse force microscopy, which testifies to the ferroelectricity of the YFeO3 film further.