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Determined the energy gap and activation energies of some transition metal complexes of liquid crystalline Schiff base.
The aim of this study is to prepare and characterize some complexes of free liquid crystal material(p-methoxybenzylidene-p-butyl aniline) (MBBA) with Cu+2, Co+2, Ni+2 and Cr+3 in order to study their electrical properties for direct current(DC) and alternative current(AC), such as: activation energy and the exponential factor, together with energy gap.
The volume resistivity measurements were performed in the temperature range between (303 to 423 K), the temperature was measured by using thermocouple that contacts the test sample from one side whereas the other side is connected with counter.
A similar effect has been reported in four (Schiff bases)complexes and their iron (III) complexes were synthesized and characterized.
The mesophases of thermotropic liquid crystals may be divided into three main groups; nematic, cholesteric and smectic phases. The nematic phase, where the rod-like molecules are ordered in the direction of the molecular long axis, although the mass centers of the molecules are not ordered. If a liquid crystal, capable of forming a nematic phase, contains a chiral carbon atom, a helical structure of the nematic phase will form. It is called cholesteric phase. In the smectic phases the molecules are ordered in layers. Different smectic phases are known. They are designated by capital letters A, B and C in chronological order of discovery (Demus and Richter, 1978).
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- energy gap , activation energies
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