Electrode free hysteresis loop measurement of small dimensional ferroelectric materials

As the basic characterization for ferroelectric material, hysteresis loop measurement based on Sawyer-Tower circuit has restrictions of electrodes, parallel plate capacitor structure and complex compensating circuit, which cannot satisfy the demand for characterization of small dimensional ferroelectric materials. In this work, a new measuring method of hysteresis loop is presented based on probes and high resolution semiconductor parameter analyzer. The capacitance of BiFeO3 film between two probes under sweeping bias voltage was measured and transformed into polarization, and the test under light illumination showed similar hysteresis loop. The hysteresis loop of small lead zirconate titanate ceramic particle was also measured. This study gives much freedom to obtain the hysteresis loop between any two points of small dimensional ferroelectric material of any shape, and to get rid of electrodes, and to conduct in situ measurement under external field.