Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 6Citation - Scopus: 6Effect of the Synthesis Method and Particle Size on Bczt Electrocaloric Properties(Pergamon-elsevier Science Ltd, 2025) Temel, Helin; Avci, Tubanur; Okatan, M. Baris; Alkoy, Sedat; Misirlioglu, I. Burc; Mensur, EbruIn this study, the electrocaloric properties of BCZT ceramics fabricated through different processing methods: solid-state and sol-gel were investigated. The calcination process was done for BCZT powders obtained by sol-gel process at 900 degrees C for 2 h and by solid-state calcination method at 1200 degrees C for 6 h. BCZT-SG ceramics exhibited higher Delta T values, particularly at lower temperatures (similar to 0 degrees C-20 degrees C), and a stronger response to the electric field, suggesting a more efficient domain structure due to sol-gel processing. Notably, BCZT-SGH samples demonstrated the most complex and pronounced electrocaloric behavior, with dual Delta T peaks around 0 degrees C and 50 degrees C, and the highest Delta T of 2.5 K at 80 kV/cm and 50 degrees C, surpassing values in the literature. Especially, high Delta T results at 0 degrees C allows using this material in the extreme conditions. These results emphasize the significant role of processing techniques in tailoring the structural, dielectric, and electrocaloric properties of BCZT ceramics for high-performance energy applications.Article Citation - WoS: 3Citation - Scopus: 4Enhancement of the Electrocaloric Effect in Pbzr0.7ti0.3o3 Ceramics Via La Doping: Driven by Phase Co-Existence or Defect Effects?(Elsevier, 2022) Gözüaçık, Namık Kemal; Bayır, Mustafa Çağrı; Okatan, Mahmut Barış; Mısırlıoğlu, I. Burç; Alkoy, Sedat; Menşur Alkoy, EbruLattice defects and their effects have been pivotal in studies of phase transitions in a wide range of materials. Introduction of such defects into a ferroelectric material through doping of secondary elements can be tailored towards specific applications but the mechanism through which the bulk properties change is seldom scrutinized. Here we study the effect of systematic La substitution into PbZr0.7Ti0.3O3 (PZT 70/30) ceramics whereby we analyzed the temperature dependent properties and estimated the temperature changes that could be induced upon application of an external electric field, namely the electrocaloric effect (ECE). Expecting the entropic changes to be maximal under an applied field, the suitability of the La doped PZT 70/30 system for EC applications had been a motivation to undertake the current task as this composition reportedly can host a rich variety of phases depending on La content including relaxor and antiferroelectric (AFE) states. An electrocaloric (EC) temperature change of 1.15 °C in a wide range of temperatures for 8% La doping at 45 kV/cm applied field was estimated from experimental data, the possible origins of which is discussed. We were able to explain the experimental results by adopting a Landau-Ginzburg based computational approach coupled with elasticity and electrostatics whereby La sites are treated as point defects in a PZT 70/30 lattice. The gradual slanting of the hystereses and reduction of the transition temperature in the samples with increasing La content is claimed to be a direct consequence of the electrical fields due to formation of dipolar defect complexes as backed by our simulations. The ECE is discussed in the light of the simulations and recent results for AFE ceramics.