Large electrocaloric effect over a wide temperature range in BaTiO3-modified lead-free ceramics

2019 ◽  
Vol 7 (5) ◽  
pp. 1353-1358 ◽  
Author(s):  
Luo Zhao ◽  
Xiaoqin Ke ◽  
Zhijian Zhou ◽  
Xiaoqi Liao ◽  
Junjie Li ◽  
...  
Keyword(s):  
Phase Transition ◽  
Wide Temperature Range ◽  
Diffuse Phase Transition ◽  
Lead Free ◽  
Broad Temperature Range ◽  
Electrocaloric Effect ◽  
Temperature Range ◽  
Lead Free Ceramics ◽  
Diffuse Phase

BT-13CH exhibits a large electrocaloric effect over a broad temperature range because of multiphase coexistence (MPC) with diffuse phase transition (DPT) character.

Diffuse Phase Transition and Dielectric Properties of Lead-Free Zr-Doped BCTS Ceramics

2017 ◽  
Vol 866 ◽  
pp. 259-262 ◽  
Author(s):  
Puripat Kantha ◽  
Kamonpan Pengpat ◽  
Nuttapon Pisitpipathsin
Keyword(s):  
Phase Transition ◽  
Dielectric Constant ◽  
Diffuse Phase Transition ◽  
Solid State Reaction Method ◽  
Lead Free ◽  
Phase Transition Behavior ◽  
Conventional Solid State Reaction ◽  
Maximum Dielectric Constant ◽  
Cubic Structure ◽  
Diffuse Phase

Lead-free Ba0.9Ca0.1Sn0.06Ti0.94-xZrxO3 (BCTSZ) ceramics where x = 0.00, 0.03, 0.05, 0.07 and 0.09 were prepared by the conventional solid-state reaction method. The dielectric constant of the Zr doped BCTS ceramic was enhanced by Zr incorporation. The maximum dielectric constant were obtained at the composition of x = 0.05. The dielectric property investigation indicated that the degree of the diffuse phase transition behavior increased with Zr substitution. Phase transition of tetragonal to cubic structure was significantly dependent on the amount of Zr added.

ELECTRICAL PROPERTIES OF (Na1/2Bi1/2)1-xCaxTiO3 CERAMICS

2002 ◽  
Vol 16 (27) ◽  
pp. 4175-4187 ◽  
Author(s):  
B. V. BAHUGUNA SARADHI ◽  
K. SRINIVAS ◽  
T. BHIMASANKARAM
Keyword(s):  
Phase Transition ◽  
Dielectric Constant ◽  
Electrical Properties ◽  
Diffuse Phase Transition ◽  
Calcium Concentration ◽  
Bismuth Titanate ◽  
Temperature Range ◽  
Impedance Data ◽  
Higher Temperature ◽  
Diffuse Phase

The frequency (100Hz–1MHz) and temperature (30–575°C) dependence of electrical properties of calcium doped (Ca = 0.01, 0.05, 0.1) sodium bismuth titanate (NBT) was investigated by impedance spectroscopy. The data is used to analyze the effect of calcium concentration on the electrical properties of NBT. The frequency explicit plots of Z′′ versus frequency at various temperatures shows peaks in the higher temperature range (>400°C). The relaxation peaks are affected by the doping. The AC conductivity values are computed from the impedance data. DC conductivity has been measured in the temperature range of 30–400°C. The activation energies have been evaluated from the data. From the studies of dielectric constant as a function of temperature, it is observed that diffuse phase transition (DPT) is exhibited in these samples.

Lead-free (Ba,Ca)(Zr,Ti)O3 Based Electrocaloric Devices: Challenges and Perspectives

2013 ◽  
Vol 1581 ◽  
Author(s):  
Gunnar Suchaneck ◽  
Gerald Gerlach
Keyword(s):  
Thin Films ◽  
Phase Transition ◽  
Electric Fields ◽  
Diffuse Phase Transition ◽  
Lead Free ◽  
Large Temperature ◽  
Temperature Changes ◽  
Diffuse Phase

ABSTRACTIn this work, we analyze the requirement to (Ba,Ca)(Zr,Ti)O3 thin films for applications in electrocaloric devices. We demonstrate that large temperature changes are realized mostly independent of the used material by applying sufficient electric fields. Ferroelectrics exhibiting a diffuse phase transition are beneficial for electrocaloric applications, but they change the range of operational temperatures.

Enhanced room temperature electrocaloric effect in barium titanate thin films with diffuse phase transition

RSC Advances ◽  
2014 ◽  
Vol 4 (42) ◽  
pp. 21826 ◽  
Author(s):  
Lijie Wang ◽  
Jinbin Wang ◽  
Bo Li ◽  
Xiangli Zhong ◽  
Fang Wang ◽  
...  
Keyword(s):  
Thin Films ◽  
Phase Transition ◽  
Barium Titanate ◽  
Diffuse Phase Transition ◽  
Room Temperature ◽  
Electrocaloric Effect ◽  
Diffuse Phase
Sign in / Sign up

Export Citation Format

Share Document