Proton conductivity and ferroelectric phase transition in hydrogen-bonded ferroelectric NH4IO3 |
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| Authors: | M M Abdel-Kader F El-Kabbany H Naguib W M Gamal |
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| Institution: | 1. Faculty of Science, Department of Physics , Cairo University , Giza, Egypt m_m_abdelkader@yahoo.com;3. Faculty of Science, Department of Physics , Cairo University , Giza, Egypt |
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| Abstract: | We report on the ac dielectric permittivity (ε) and the electric conductivity (σω), as function of the temperature 300?K?T4IO3. The main feature of our measured parameters is that, the compound undergoes a ferroelectric phase transition of an improper character, at (368?±?1)K from a high temperature paraelectric phase I (Pm21 b) to a low temperature ferroelectric phase II (Pc21n). The electric conduction seems to be protonic. The frequency dependent conductivity has a linear response following the universal power law (σ( ω )?=?A(T)ω s (T)). The temperature dependence of the frequency exponent s suggests the existence of two types of conduction mechanisms. |
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| Keywords: | Phase transition Ammonium iodate NH4IO3 Proton conductivity Improper ferroelectric |
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