Structural phase transition, vibrational analysis, ionic conductivity and conduction mechanism studies in an organic-inorganic hybrid crystal: [N(CH3)3H]2CdCl4

Abstract Hybrid organic-inorganic metal halides ( HOMHs ) present good application prospects in optoelectronics and photovoltaic as a result of their richness in physical properties and diverse structural assemblies. Herein, the organic-inorganic hybrid compound, [N(CH3)3H]2CdCl4 ( 1 ) is successfully synthesized by slow evaporation at room temperature. X-ray powder diffraction shows that 1 crystallizes in the orthorhombic system with the space group P n a 2 1 . The chemical composition of 1 is discussed by a STEM − EDS . Two-phase transitions at T 1 = 253 / 263 K and T 2 = 290 / 300 K are confirmed by the differential scanning calorimetry (DSC) curve. The measurements of the electrical properties are performed in the 10 − 1 − 10 7 Hz frequency range and 220 − 335 K temperature interval. The study on the charge transfer mechanism of 1 is done with the help of Elliott’s theory. The conduction mechanism in 1 is interpreted by different approaches: the correlated barrier hopping ( C B H ) model in phase I, the non-overlapping small polaron tunneling ( N S P T ) model in phase II, and the overlapping large polaron tunneling ( O L P T ) model in phase III.