Studies on structural, electrical, and transport properties of [(C3H7)4N]2Cu2Br6 compound

Abstract

The new organic–inorganic compound [(C3H7)4N]2Cu2Br6 has been synthesized by slow evaporation method at room temperature and characterized by single X-ray diffraction, differential scanning calorimetry and impedance spectroscopy. In fact, the latter is crystallized at room temperature in the triclinic system (P1¯ space group) with the following unit cell parameters: a = 9.578(2)Å, b = 9.578(2)Å, c = 11.964(2)Å, α = 102.138(6), β = 104.518(3) and γ = 112.747(6). The atomic arrangement can be described by an alternation of organic and inorganic layers stacked along [11¯1¯] direction and made up of [N(C3H7)4]+ and [CuBr3]- groups, respectively. The differential scanning calorimetry (DSC) studies disclose a presence of phase transitions located at 353 K. In addition, some electrical characteristics of (impedance, conductivity, and modulus) of the sample have been investigated in a wide range of frequency (100 Hz-2MHz) and temperature (330–375 K) ranges. Both impedance and modulus analysis exhibit the grain and grain boundary contribution to the electrical response of the sample. The equivalent circuit is modeled by a combination series of two parallel RP–CPE circuits. The temperature dependence of the alternative current conductivity (σg) and bulk relaxation frequency (ωp) confirm the observed transitions in the calorimetric study. Moreover, the temperature dependence study of frequency exponent (s) is investigated to explain the conduction mechanism in the different parts, which is attributed to the non overlapping small polaron tunneling (NSPT) in the region I and II.