Fig. 4: The variation of dielectric constant (Top) and loss tangent (Bottom) with measure AC voltage (Ṽ) and DC bias voltage (V) under dark (black) and illumination (red) conditions, respectively.
From: Ultra sensitive low-frequency visible light dielectric response measured by real capacitance method

a SmCrO3 sample with AC measure voltage at 100 Hz. b SmTi0.05Cr0.95O3 sample with AC measure voltage at 100 Hz. c SmCrO3 sample with frequency and DC bias voltage. d SmTi0.05Cr0.95O3 sample with DC bias voltage at 100 Hz.