Nilaya K. Mohanty; Ajay K. Behera; Santosh K. Satpathy; Banarji Behera; Pratibindhya Nayak
Abstract
The Gd-modified BiFeO3-PbTiO3 composites i.e. 0.5BiGdxFe1-xO3-0.5PbTiO3 (BGxF1-x-PT) with x=0.00, 0.05, 0.10, 0.15, 0.20, were prepared by mixed oxide method at high temperature. The structural study reveals that the composites showed tetragonal crystal structure at room temperature and tetragonality ...
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The Gd-modified BiFeO3-PbTiO3 composites i.e. 0.5BiGdxFe1-xO3-0.5PbTiO3 (BGxF1-x-PT) with x=0.00, 0.05, 0.10, 0.15, 0.20, were prepared by mixed oxide method at high temperature. The structural study reveals that the composites showed tetragonal crystal structure at room temperature and tetragonality (c/a ratio) of composites decrease with increase in Gd concentration. The average crystallite size of the composites was found to be in the range of 30-89 nm. Surface morphology of the composites was studied by scanning electron microscopy (SEM). The Goldschmidt tolerance factors of the composites were found to be in the range of 0.989-0.976. The nature of Nyquist plot confirmed the presence of both bulk and grain boundary effects, and non-Debye type of relaxation process occur in the composites. The activation energy of the composites was found to be in the range 0.13-1.38eV. The analyses of ac conductivity data obey the universal agreement with Jonscher’s power law. Further, the explanation of conduction mechanism through correlated barrier hopping (CBH) model was discussed.
Ajay Kumar Behera; Nilaya K. Mohanty; Banarji Behera; Pratibindhya Nayak
Abstract
The polycrystalline sample of 0.7(BiFeO3)-0.3(PbTiO3) [0.7(BFO)-0.3(PT)] was prepared by a high temperature solid state reaction technique. Studies of structural analysis confirm the formation of the compound with rhombohedral structure at room temperature. The electrical properties (impedance, modulus ...
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The polycrystalline sample of 0.7(BiFeO3)-0.3(PbTiO3) [0.7(BFO)-0.3(PT)] was prepared by a high temperature solid state reaction technique. Studies of structural analysis confirm the formation of the compound with rhombohedral structure at room temperature. The electrical properties (impedance, modulus and conductivity) of the material were analyzed using a complex impedance spectroscopy technique in a wide temperature (225-300 o C) and frequency (10 2 -10 6 Hz) range. The studied material exhibits a significant contribution of grain (bulk) effect and non-Debye of relaxation process. The bulk resistance decreases with rise in temperature which exhibits negative temperature coefficient of resistance (NTCR) behavior. Electrical modulus study confirms the presence of bulk effect in the material. This compound also exhibits the temperature dependence of relaxation phenomena. The ac and dc conductivity of the materials were found to be increase with increase in temperature. The activation energy of the compound is found to be less than 1eV and suggests the conduction process is of mixed type (ionic-polaronic and singly-ionized oxygen ion vacancies).