Structural, AC conductivity and dielectric properties of bulk 1,3-Dihydro-1,3,3-trimethylspiro[2H-indole-2,3′-[3H]naphth[2,1-b][1,4]oxazine]

The frequency dependent of the AC conductivity and Dielectric properties of organic compound 1,3-Dihydro-1,3,3-trimethylspiro [2H-indole-2,3′-[3H] naphth [2,1-b] [1,4] oxazine], SPO, have been studied as a bulk in a frequency range (50 Hz–5 MHz) with different temperature. X-ray diffraction (XRD) and high-resolution transmission electron microscope (HRTEM) suggest that the SPO compound has polycrystalline with monoclinic structure, space group P21 along with crystalline size around 35 nm at room temperature. The obtained results of AC conductivity, σ (ω), increased with increasing frequency. Consequently, the exponent frequency factor, S, was estimated and found to be S < 1 and increase with increasing temperature. This behavior indicates that the small Polaron (SP) model is the most predominated conduction mechanism. The dielectric properties including dielectric constant, dielectric loss and loss tangent were found to be decreased with increasing frequency, while these parameters are increased with increasing the temperature in the investigated ranges. Moreover, the activation energy, the relaxation time and the maximum barrier height were extracted.