Abnormal C–V curve and clockwise hysteresis loop in ferroelectric barium stannate titanate ceramics

Reversible hysteresis loop, defined as integral of small signal dielectric constant with electrical field, represents the contribution of the reversible part of polarization. In barium stannate titanate ceramics, field dependence of small signal dielectric constant was abnormal. The subsequent mathematical integral showed an abnormal clockwise hysteresis loop in the temperature range of 10–40 °C. The ferroelectric hysteresis loop measured by Sawyer–Tower circuit showed slim-waist or pinched shape. This phenomenon may reveal abnormal domain switching mechanism and is believed to be related with the strong interaction between point defects and domain walls.