Effect on Electrical Properties of Gd-Doped BiFeO3–PbZrO3 (original) (raw)

2019, Iranian Journal of Science and Technology, Transactions A: Science

The (1 − x)(BiFe 1−y Gd y O 3)−x(PbZrO 3) [x = 0.5, y = 0.05, 0.10, 0.15, 0.20] were synthesized using a high-temperature solidstate reaction technique. X-ray analysis confirms the formation of the composites. The dielectric properties of the composites were studied. The hysteresis loop suggested that the materials were lossy. The impedance parameters were studied in a wide range of frequency (10 2-10 6 Hz) at different temperatures for all samples. The Nyquist plot suggested the contribution of bulk effect as well as grain boundary effect and the bulk resistance deceased with a rise in temperature for all the samples. The electrical transport confirmed the presence of hopping mechanism in the materials. The dc conductivity of the materials increased with a rise in temperature. The frequency variation of ac conductivity obeyed the Jonscher's universal power law and confirmed the small polaron (SP) tunneling effect due to low activation energy for all the samples. Temperature dependence of dc and ac conductivity indicated the thermally activated process of the materials.

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Effect of Electrical Properties on Gd modified BiFeO3-PbZrO3

The 0.5(BiGdxFe1-xO3)-0.5(PbZrO3) composite was synthesized using a high temperature solid-state reaction technique. Preliminary X-ray structural analysis confirms the formation of the composite. The dielectric constant and loss tangent have been studied. The hysteresis loop suggest that the material is lossy. The impedance parameters were studied using an impedance analyzer in a wide range of frequency (102-106 Hz) at different temperatures for all samples. The Nyquist plot suggests the contribution of bulk effect as well as grain boundary effect and the bulk resistance deceases with rise in temperature for all samples. The electrical transport confirms the presence of hopping mechanism in the material. The dc conductivity increases with rise in temperature. The frequency variation of ac conductivity shows that the compound obeys Jonschers universal power law and confirms the Small Polaron (SP) tunneling effect due to low activation energy for all samples. Temperature dependence of...

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Materials Science-Poland, 2014

The 0.5(BiGd 0.05 Fe 0.95 O 3)-0.5(PbZrO 3) composite was synthesized by means of a high temperature solid-state reaction technique using high purity ingredients. Preliminary X-ray structural analysis confirms the formation of the composite. The dielectric constant and loss tangent have been studied. The impedance parameters have been measured using an impedance analyzer in a wide range of frequency (10 2-10 6 Hz) at different temperatures. The Nyquist plot suggests the contribution of bulk effect only and the bulk resistance decreases with a rise in temperature. Electrical impedance confirms the presence of grain effect and hopping mechanism in the electrical transport of the material. The dc conductivity increases with a rise of temperature. The frequency variation of ac conductivity shows that the compound obeys Jonscher's universal power law and from Jonscher's power law fit confirms the Small Polaron (SP) tunneling effect. Temperature dependence of dc and ac conductivity indicates that electrical conduction in the material is a thermally activated process.

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Journal of Advanced Dielectrics, 2017

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Applied Physics A, 2006

The polycrystalline (Bi 1−x Pb x)(Fe 1−x Zr 0.6x-Ti 0.4x)O 3 (x = 0.15, 0.25, 0.40, 0.50) (BPFZT) nanoceramic composites were synthesized using mechanical activation and solid-state reaction techniques. The formation of single-phase compounds with 100% solubility of BiFeO 3 and Pb(Zr 0.6 Ti 0.4)O 3 was confirmed by an X-ray diffraction (XRD) technique. Detailed structural analysis of the fabricated BPFZT composites suggests the formation of tetragonal structure (i.e., distorted perovskite) for all composition. The dielectric constant and loss-tangent of the BPFZT composites decrease on increasing frequency and temperature. It has also been observed that the leakage current and loss-tangent are reduced by increasing the contents of PZT in the BPFZT composites, and hence they may be considered useful for some applications. The values of activation energies and the nature of variation of conductivity with temperature and frequencies suggest that the space charge and oxygen ion vacancies play a significant role in the conduction process.

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Journal of Rare Earths, 2015

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Influence Of Gd On Structural And Impedance Properties Of Multiferroic Composites: BiFeO3-PbTiO3

Advanced Materials Letters, 2015

The Gd-modified BiFeO 3-PbTiO 3 composites i.e. 0.5BiGd x Fe 1-x O 3-0.5PbTiO 3 (BG x F 1-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.

Structural and electrical properties of Bi3TiVO9 ferroelectric ceramics

Journal of Alloys and Compounds, 2018

Bi 3 TiVO 9 (BTV), a member of Aurivillius family, has been fabricated by a mixed-oxide route at high temperature. Room temperature structural analysis using X-ray diffraction data confirms the crystallization of ceramic in the orthorhombic crystal structure. Surface morphological analysis using field-emission scanning electron microscopic (FESEM) images and elemental study with energy dispersive X-ray spectroscopy (EDX) reveal the uniform distribution of grains and compositional elements of the prepared material, respectively. Based on the temperature and frequency dependence of capacitive and resistive parameters, the electrical phenomena underlying the sample are discussed. The contribution of grain and grain boundary towards the conduction and relaxation mechanism is described by the complex impedance spectroscopy. The semi-conducting property (negative temperature coefficient of resistance (NTCR)) behavior is observed from the temperature dependent bulk resistance and J~E characteristics of the sample. The frequency dependent ac conductivity of the system obeys the universal Jonscher's power law with conduction mechanism based on overlappinglarge polaron tunneling model and correlated barrier hopping model. Measurement of room temperature hysteresis loop confirms the existence of ferroelectricity in the sample.

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