فهرس المقالات Ferroelectric

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  1 - Dopant and milling time effect on impedance and electrical properties of perovskite ceramics
  Shristi Chaudhary Mikanshi Chaudhary Sheela Devi Shilpi Jindal
  10.57647/J.JTAP.2023.1702.22
  Tungsten doped Barium Titanate (BT) with composition BaW0.05Ti0.95O3 (BWT) were prepared by using ball milling technique for different hours (10h, 20h and 30h). In the present paper, the microstructural, dielectric and impedance studies are discussed. The microstructura أکثر

  Tungsten doped Barium Titanate (BT) with composition BaW0.05Ti0.95O3 (BWT) were prepared by using ball milling technique for different hours (10h, 20h and 30h). In the present paper, the microstructural, dielectric and impedance studies are discussed. The microstructural studies using XRD data reveals the formation of single phased tetragonal structure and perovskite structure. The dielectric properties of BT nanoceramics were significantly enhanced by the partial replacement of W (at B site) showing the diffuse phase transition at 80°C. Dielectric loss rises as the temperature rises. There is increase in charge carrier mobility which results in increased polarization and significant dielectric loss. Additionally, compared to the un-milled BWT ceramic sample, the 30h milled had superior dielectric characteristics with high dielectric constant and reduced loss. The nature of the phase transition was confirmed by the Curie-Weiss law and the ferroelectric analysis was carried by well-established P-E loops. The impedance studies were carried out by plotting Nyquist plots. The ac conductivity plot follows Arrhenius relation and the calculated activation energy confirms the negative temperature coefficient of resistance (NTCR) behavior of the material. تفاصيل المقالة
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  2 - Temperature dependence dielectric behavior of Ge-doped lead scandium tantalate single crystals
  Chandra Kumar Dixit Anil Kumar Srivastava
  10.1186/2251-7235-6-8
  AbstractThe doping of Pb2SeTaO6 with Ge ferroelectrics was produced by a high-temperature solution method. We measure dielectric constant, dielectric loss and conductivity in the temperature range −30°C to 200°C and frequency range 1 to 100 KHz. The value of dielectric أکثر

  AbstractThe doping of Pb2SeTaO6 with Ge ferroelectrics was produced by a high-temperature solution method. We measure dielectric constant, dielectric loss and conductivity in the temperature range −30°C to 200°C and frequency range 1 to 100 KHz. The value of dielectric constant of the Pb2SeTaO6 (PST) crystal remained the same after thermal annealing whereas they decreased after Ge doping in the phase transition temperature range of the PST single crystal. All samples were investigated for conductivity with increasing temperature. تفاصيل المقالة
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  3 - Designing Tunable Optical Filter multi-Channel containing 1DDPC Structure
  Behnam Kazempour
  An electro-optic tunable single and multi-channel optical filter based on one-dimensional defective photonic crystal (1DDPC) structure is proposed. A couple of externally tunable defects in arrangement of (AB)5D1(BA)D2(BA)5, where A and B are dielectric materials, D1 an أکثر

  An electro-optic tunable single and multi-channel optical filter based on one-dimensional defective photonic crystal (1DDPC) structure is proposed. A couple of externally tunable defects in arrangement of (AB)5D1(BA)D2(BA)5, where A and B are dielectric materials, D1 and D2 are the tunable defects are used. The defects are composed of the ferroelectric LiNbO3 crystals and two pairs of thin Ag layers to make the voltage connections. With this arrangement it is possible to apply different external biases that facilitate the tunability and even more adjustability of the channel frequencies. Depending on the thickness of defect layers, a single or multi resonant peak can be induced inside the photonic band gap which can be employed to filter channels. About 37 nm (46 nm) of blue shift for 300 V and 37 nm (37 nm) of red shift for -300 V biases are observed without (and with) loss incorporation. An important and notable effect that happened was the dispersion loss of the structure due to metal layers is compensated by the negative biases. Our proposed structure can be good candidate to design an externally tunable optical filter and a voltage sensor with potential applications in all-optical signal processing and information communications fields. تفاصيل المقالة
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  4 - Influence of heat treatment on synthesis of stoichiometric perovskite PbTiO3 nanostructure via hydrothermal method
  Sahebali Manafi
  10.22034/jna.2020.1882166.1169
  In this research, the stoichiometric perovskite lead titanate (PbTiO3) nanostructure was synthesized successfully by the hydrothermal method. The effect of heat treatment of the autoclave and the furnace on the structure of this material was investigated. Titanium dioxi أکثر

  In this research, the stoichiometric perovskite lead titanate (PbTiO3) nanostructure was synthesized successfully by the hydrothermal method. The effect of heat treatment of the autoclave and the furnace on the structure of this material was investigated. Titanium dioxide (TiO2), titanium tetrachloride (TiCl4) and lead oxide (PbO), lead nitrate (Pb(NO3)2) were used as the titanium and lead sources, respectively. The negative amount of the Gibbs free energy shows the reactivity of the reaction at room temperature. Characterization of PbTiO3 was carried out using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The amount of lead titanate increased by raising the temperature of the autoclave. The objective of this research was developing the hydrothermal method to produce the phase-pure lead titanate at lower temperatures; also the effect of the precursor materials and heat treatment on morphology and crystal grows the development of PbTiO3 nanopowders were investigated. There are not any secondary phases when the sample was calcined at high temperatures. It seemed that heating in the furnace in a longer period and higher temperatures could affect the size of the crystallites. The powder was heated at 1200 ℃ had the larger grains and the ferroelectric domains that may cause the lowering of the dielectric constant. تفاصيل المقالة
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  5 - Influence of heat treatment on synthesis of stoichiometric perovskite PbTiO3 nanostructure via hydrothermal method
  Sahebali Manafi Sedigheh Joughehdoust
  10.22034/jna.2020.677393
  In this research, the stoichiometric perovskite lead titanate (PbTiO3) nanostructurewas synthesized successfully by the hydrothermal method. The effect of heattreatment of the autoclave and the furnace on the structure of this materialwas investigated. Titanium dioxide أکثر

  In this research, the stoichiometric perovskite lead titanate (PbTiO3) nanostructurewas synthesized successfully by the hydrothermal method. The effect of heattreatment of the autoclave and the furnace on the structure of this materialwas investigated. Titanium dioxide (TiO2), titanium tetrachloride (TiCl4) and leadoxide (PbO), lead nitrate (Pb(NO3)2) were used as the titanium and lead sources,respectively. The negative amount of the Gibbs free energy shows the reactivityof the reaction at room temperature. Characterization of PbTiO3 was carried outusing scanning electron microscopy (SEM), transmission electron microscopy(TEM) and X-ray diffraction (XRD). The amount of lead titanate increased by raisingthe temperature of the autoclave. The objective of this research was developingthe hydrothermal method to produce the phase-pure lead titanate at lowertemperatures; also the effect of the precursor materials and heat treatment onmorphology and crystal grows the development of PbTiO3 nanopowders wereinvestigated. There are not any secondary phases when the sample was calcinedat high temperatures. It seemed that heating in the furnace in a longer periodand higher temperatures could affect the size of the crystallites. The powder washeated at 1200 oC had the larger grains and the ferroelectric domains that maycause the lowering of the dielectric constant. تفاصيل المقالة