Abstract
Dielectric and electrical properties correlated with the structure analysis have been studied for new crystalline polymer {(C2H10N2)(MnCl (NCS)(2))(2)}(n). The frequency and temperature dependence of dielectric constant (epsilon '), dielectric loss (epsilon '') and loss tangent (tan delta) in the temperature range 308-348 K and frequency range 20 to 2 MHz have been made for {(C2H10N2)(MnCl (NCS)(2))(2)}(n). The Z ' and Z '' versus frequency plots are well fitted to an equivalent circuit model. The analysis of Nyquist plots is well fitted to an equivalent circuit consisting of series of combination of grains and grain boundary elements. The spectra follow the Arrhenius law with two activation energy the first in the region of temperatures before 332 K (Region I) and the second in the region after 332 K (Region II). An agreement between the experimental and theoretical results is discussed, and it is suggested that the ac conductivity can be explained by the correlated barrier hopping (CBH) and nonoverlapping small polaron tunneling model (NSPT) in regions I and II, respectively. The AC conduction mechanism is governed by the correlated barrier-hopping (CBH) with W-M(Region I) = 270 meV and a tunneling distance of 4.5 angstrom, whereas it becomes a small polaron tunneling mechanism (SPTM) mechanism with a W-H(Region II) = 153 meV. The imaginary part of the electrical modulus formalism obeys the Kohlrausch-Williams-Watt (KWW) model. The theoretical Kohlrausch exponent (beta(KWW)) confirms the existence of the transition phase on the new crystalline polymer in the vicinity of the 332 K as deduced by the DC and the AC conduction parameters. Thus, the near values of activation energies obtained from the impedance and modulus spectra confirm that the transport is through an ion hopping mechanism.