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Title: Unification of the negative electrocaloric effect in Bi{sub 1/2}Na{sub 1/2}TiO{sub 3}-BaTiO{sub 3} solid solutions by Ba{sub 1/2}Sr{sub 1/2}TiO{sub 3} doping

The microscopic mechanisms of the negative electrocaloric effect (ECE) of the single-phase (1−x)(0.94Bi{sub 1/2}Na{sub 1/2}TiO{sub 3}-0.06BaTiO{sub 3})-xBa{sub 1/2}Sr{sub 1/2}TiO{sub 3} (BNT-BT-BST) perovskite solid solutions fabricated via the sol-gel technique are explored in this study. Dielectric and mechanical relaxation analyses are employed to investigate the ferroelectric and structural transitions of the samples. The electrocaloric properties of the samples were measured by thermodynamics Maxwell relations. The difference between the depolarization temperature (T{sub d}) and the maximum dielectric constant temperature (T{sub m}) was found to decrease with increasing BST content. Doping with BST stabilized the ferroelectric phase along with unifying the EC temperature changes (ΔT) to only negative values. The origin of the uniform negative ECE of BNT-BT-BST is discussed.
Authors:
 [1] ;  [2] ;  [1] ;  [3] ;  [4] ;  [5] ;  [6]
  1. Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong)
  2. (Pakistan)
  3. (China)
  4. Materials Research Laboratory, Institute of Physics and Electronics, University of Peshawar, Peshawar 25120 (Pakistan)
  5. Department of Materials Science and Engineering, Boise State University, Boise, Idaho 83725-2090 (United States)
  6. School of Materials Science and Engineering, The University of Shanghai for Science and Technology, Shanghai (China)
Publication Date:
OSTI Identifier:
22258691
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 114; Journal Issue: 21; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; DEPOLARIZATION; FERROELECTRIC MATERIALS; PERMITTIVITY; PEROVSKITE; RELAXATION; SOL-GEL PROCESS; SOLID SOLUTIONS; THERMODYNAMICS; THERMOELECTRIC PROPERTIES; TITANATES