High Efficiency Refrigeration and Pyroelectric Energy Harvesting Applications of Lead Titanate Based Relaxer Ceramic

2020 ◽  
Author(s):  
Tianfu Zhang ◽  
Xianxiong Huang ◽  
Hu Xu ◽  
Shujie Sun ◽  
Zuodong Liu ◽  
...  
Keyword(s):  
Phase Transition ◽  
Solid State ◽  
Energy Harvesting ◽  
High Efficiency ◽  
Ferroelectric Properties ◽  
Solid State Reaction Method ◽  
Temperature Dependent ◽  
Maximum Value ◽  
Phase Transition Temperatures ◽  
Potential Applications

Abstract Relaxer ferroelectrics are highly attractive in electrocaloric due to large breakdown electric field and wide phase transition temperatures, which has great potential applications in solid-state cooling. In this work, relaxer ferroelectrics are synthesized by a traditional solid state reaction method. Phase transition and relaxer characteristics are studied by temperature dependent dielectric spectrums. Temperature dependent ferroelectric properties are also studied to calculate electrocaloric effect. Maximum value of refrigeration efficiency η ( ΔT/ΔE ) is about 0.079 K·cm/kV, our result lays a foundation and provides a reference for studying high efficiency solid-state electrocaloric refrigeration. Pyroelectric energy harvesting are studied, maximum pyroelectric energy harvesting is 279 kJ/cm 3 .

Effects of (Li, Ce) Co-Doping on Microstructure, Dielectric and Ferroelectric Properties of Strontium Niobate Ceramics

2014 ◽  
Vol 787 ◽  
pp. 236-241 ◽  
Author(s):  
Gang Chen ◽  
Jie Hao Wei ◽  
Xiao Dong Peng ◽  
Chun Lin Fu ◽  
Wei Cai
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Solid State ◽  
Remnant Polarization ◽  
Ferroelectric Properties ◽  
Solid State Reaction Method ◽  
Reaction Method ◽  
Co Doping ◽  
Maximum Value ◽  
Coercive Electric Field

Sr2-x(Li2/3, Ce1/3)x Nb2O7 (x = 0, 0.05, 0.1, 0.2, 0.3, 0.5) (SLCN) ceramics were prepared by solid-state reaction method. The microstructure, dielectric and ferroelectric properties were investigated. The results show that all ceramics have high relative densities. Li+ and Ce4+ co-doping can promote the grains growing, and improve the dielectric and ferroelectric properties of strontium niobate ceramics. The dielectric constant decreases firstly, and then increases with the increasing of x in Sr2-x(Li2/3, Ce1/3)x Nb2O7, and the sample with x = 0.5 exhibits enhanced dielectric properties (εr ≈ 250, tanδ ≈ 0.02). The remnant polarization (Pr) and coercive electric field (Ec) of SLCN ceramics increase firstly, and then decrease with the increasing of Li+ and Ce4+ content, finally reach the maximum value of remnant polarization (Pr ≈ 0.058μC/cm2, Ec ≈ 6.87 kV/cm ) for x = 0.2.

Dielectric and Ferroelectric Properties of (Pb0.9Ba0.1) ZrO3 Ceramics

2011 ◽  
Vol 687 ◽  
pp. 247-250
Author(s):  
Jun Bo Wu ◽  
Xin Gui Tang ◽  
Qiu Xiang Liu ◽  
Yan Ping Jiang
Keyword(s):  
Phase Transition ◽  
Room Temperature ◽  
Ferroelectric Properties ◽  
Solid State Reaction Method ◽  
Ferroelectric Hysteresis Loop ◽  
Dielectric Measurements ◽  
Reaction Method ◽  
Maximum Value ◽  
Ferroelectric Hysteresis ◽  
Maximum Permittivity

(Pb1-xBax)ZrO3(PBZ) ceramics forx= 0.10 were synthesized by the mixed oxide solid state reaction method. Phase transition was investigated by dielectric measurements in the temperature range from 27 to 350 °C at various frequencies. The permittivity of the solids corresponding to (Pb1-xBax) ZrO3showed the maximum value of 10220 atx= 0.10 at the phase transition temperature. The maximum permittivity gradually increasing concentration up tox= 0.10. The ferroelectric hysteresis loop of the PBZ ceramics forx= 0.10 is displayed at room temperature and 0.2 Hz.

Temperature-Dependent Solid-state Luminescence and Reversible Phase Transition of (n-Bu4N)[Au(SC6H3-3,5-Me2)2]

2003 ◽  
Vol 32 (11) ◽  
pp. 1002-1003 ◽  
Author(s):  
Seiji Watase ◽  
Takayuki Kitamura ◽  
Nobuko Kanehisa ◽  
Masami Nakamoto ◽  
Yasushi Kai ◽  
...  
Keyword(s):  
Phase Transition ◽  
Solid State ◽  
Temperature Dependent ◽  
Reversible Phase Transition ◽  
Reversible Phase ◽  
State Luminescence

Study on Dielectric and Ferroelectric Properties of Gd-Doped Sr2Bi4Ti5O18 Ceramics

2011 ◽  
Vol 328-330 ◽  
pp. 1131-1134
Author(s):  
Qian Chen ◽  
Zhi Jun Xu ◽  
Rui Qing Chu ◽  
Yong Liu ◽  
Ming Li Chen ◽  
...  
Keyword(s):  
Piezoelectric Properties ◽  
Ferroelectric Properties ◽  
Solid State Reaction Method ◽  
Lead Free ◽  
Structural Ceramics ◽  
Conventional Solid State Reaction ◽  
Reaction Method ◽  
Maximum Value ◽  
Pure Bismuth ◽  
Ferroelectric And Piezoelectric Properties

Lead-free piezoelectric ceramics Sr2Bi4-xGdxTi5O18 were prepared by conventional solid-state reaction method. Pure bismuth layered structural ceramics with uniform gain size were obtained in all samples. The effect of Gd-doping on the dielectric, ferroelectric and piezoelectric properties of Sr2Bi4Ti5O18 ceramics were also investigated. It was found that that Gd3+ dopant gradually decreased the Curie temperature (Tc) with the lower dielectric loss (tand) of SBTi ceramics. In addition, Gd-doping with appropriate content improved the ferroelectric and piezoelectric properties of the SBTi ceramics. The piezoelectric constant (d33) of the Sr2Bi3.9Gd0.1Ti5O18 ceramic reached the maximum value, which is 22 pC/N. The results showed that the Sr2Bi4-xGdxTi5O18 ceramic was a promising lead-free piezoelectric material.

Change of Phase Transition Temperature in Band Engineered Ferroelectric Lanthanum-Modified Bismuth Titanates

2020 ◽  
Vol 20 (11) ◽  
pp. 7135-7139
Author(s):  
Rui Tang ◽  
Sangmo Kim ◽  
Chung Wung Bark
Keyword(s):  
Phase Transition ◽  
Dielectric Constant ◽  
Transition Temperature ◽  
Phase Transition Temperature ◽  
Ferroelectric Properties ◽  
Solar Spectrum ◽  
Ferroelectric Material ◽  
Transition Temperatures ◽  
Phase Transition Temperatures ◽  
Increasing Temperature

The ferroelectric material chosen for a solar cell has to absorb as much of the solar spectrum as possible, therefore a low band gap is desirable, but it is rarely known for phase transition temperature on the bandgap engineered ferroelectric materials. The phase transition temperature of a ferroelectric material can be determined by monitoring its dielectric constant with increasing temperature, as the dielectric constant changes abruptly at the phase transition temperature. Here, we inform the measurement of the phase transition temperature of the ferroelectric complex oxide Bi3.25La0.75Ti3O12 as well as cobalt and iron doped Bi3.25La0.75Ti3O12 bulk ceramics for photovoltaic cells based on dielectric monitoring with changing temperature. We synthesized lanthanum-modified bismuth-titanate-based ceramics with various doping concentrations transition metal to Ti. X-ray diffraction analysis revealed that all the compounds crystallized in an orthorhombic structure. Their morphologies and size distributions were observed using scanning electron microscopy. From the ultraviolet-visible spectroscopy absorption spectra of the synthesized powder, bandgaps were checked. An inductance-capacitance-resistance meter was used to obtain the relationship between dielectric responses and the temperature of the targets in a tube furnace. We observed that the dielectric constant increases gradually with increasing temperature, until the transition temperature and subsequently decreases, and we were able to determine the phase transition temperatures of the tested materials. Furthermore, the results revealed that all the doped bismuth titanates keep their phase transition temperatures, which were sufficiently high, to maintain their ferroelectric properties above room temperature.

Structural, dielectric and magnetic properties of Pr-, Tb- and Dy-doped (Bi0.95RE0.05)(Fe0.95Mn0.05)O3 ceramics synthesized by solid-state reaction method

2013 ◽  
Vol 03 (04) ◽  
pp. 1350033 ◽  
Author(s):  
Radheshyam Rai ◽  
Shweta Thakur ◽  
M. A. Valente ◽  
Andrei L. Kholkin
Keyword(s):  
Magnetic Properties ◽  
Solid State ◽  
Solid State Reaction ◽  
Magnetic Measurements ◽  
Ferroelectric Properties ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Solid State Reaction Technique ◽  
X Ray ◽  
Ceramic Samples

The multiferroic ( Bi 0.95 RE 0.05)( Fe 0.95 Mn 0.05) O 3 (where RE = Pr , Tb and Dy ) has been synthesized using solid-state reaction technique. Effects of Pr , Tb and Dy substitution on the structure, electrical and ferroelectric properties of ( Bi 0.95 RE 0.05)( Fe 0.95 Mn 0.05) O 3 samples have been studied by performing X-ray diffraction, dielectric measurements and magnetic measurements. The crystal structure of the ceramic samples have a monoclinic phase. The vibrating sample magnetometer (VSM) measurement shows a significant change in the magnetic properties of Pr -, Tb - and Dy -doped ( Bi 0.95 RE 0.05)( Fe 0.95 Mn 0.05) O 3. It is seen that coercive field (Hc) and remanent magnetization (Mr) increases for Pr but decreases for Dy and Tb .

Two In-Based Organic−Inorganic Hybrid Compounds with Reversible Phase Transition Derived from Order-Disorder Changes of Cations or Anions

2021 ◽  
Author(s):  
Yin-Qiang Zhang ◽  
Guan-Cheng Xu ◽  
Min Li
Keyword(s):  
Phase Transition ◽  
Solid State ◽  
Physical Properties ◽  
Ferroelectric Properties ◽  
Inorganic Hybrid ◽  
Hybrid Compounds ◽  
Reversible Phase Transition ◽  
Reversible Phase

Solid-state phase transition materials have been received extraordinary interest due to their rich physical properties, such as the thermal, dielectric, and ferroelectric properties. Here, two In-based organic-inorganic hybrid compounds, (C6H5CH2CH2NH3)3[InBr5(H2O)]...

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