Scholarlink

<p>(Ba,Ca)(Zr,Ti)O<sub>3</sub> (BCZT) is a lead-free perovskite oxide with promising applications in electronic, ferroelectric, and optoelectronic devices. Understanding its growth mechanisms and structure–property correlations in thin films is essential for device optimization. In this work, BCZT thin films were deposited via pulsed laser deposition (PLD) at substrate temperatures ranging from room temperature (RT) to 700&#xa0;°C and systematically investigated to reveal their structural, chemical, microstructural, optical, and electrical evolution. Ti K-edge XANES showed distinct pre-edge peaks A (4968.6&#xa0;eV) and B (4969.65&#xa0;eV), corresponding to 1&#xa0;s → 3d (t₂g) and 1&#xa0;s → eg transitions, confirming enhanced octahedral symmetry, stronger Ti–O covalency, and a stable Ti<sup>4</sup>⁺ state (edge at 4979.5&#xa0;eV) with increasing temperature. XPS analysis revealed a shift in film composition from Ba<sub>0.73</sub>Ca<sub>0.05</sub>Zr<sub>0.12</sub>Ti<sub>0.10</sub>O<sub>3</sub> (pristine) to Ba<sub>0.51</sub>Ca<sub>0.08</sub>Zr<sub>0.11</sub>Ti<sub>0.30</sub>Oₓ after annealing at 700&#xa0;°C, indicating Ba depletion, improved Ca incorporation, and increased Ti content, consistent with cation redistribution toward balanced perovskite stoichiometry. Grazing incidence X-ray diffraction (GI-XRD) confirmed amorphous growth below 600&#xa0;°C, perovskite crystallization at 600&#xa0;°C (crystallite size ~ 9.5&#xa0;nm), and tetragonal polycrystallinity at 700&#xa0;°C (7.0&#xa0;nm) with reduced dislocation density (~ 10<sup>15</sup>&#xa0;m⁻<sup>2</sup>). FE-SEM showed grain refinement from ~ 18&#xa0;nm (RT) to ~ 10&#xa0;nm (700&#xa0;°C) with smoother surfaces. The ferroelectric studies revealed a clear evolution from paraelectric to well-defined ferroelectric behavior with increasing deposition temperature, with the 700&#xa0;°C films exhibiting saturated, square P–E loops and high remanent polarization (~ 29.5 µC/cm<sup>2</sup>), confirming the formation of stable switchable domains.Optical studies revealed high visible transmittance (75–85%), a reduction in refractive index at 550&#xa0;nm from 2.257 (RT) to 2.184 (700&#xa0;°C), and film thickness decrease from 317 to 230&#xa0;nm. The optical bandgap narrowed slightly from 3.93 to 3.82&#xa0;eV, correlating with improved crystallinity and densification. Overall, this study highlights how deposition temperature governs the structural ordering, chemical stoichiometry, and optical response of BCZT thin films, providing insights for tailoring lead-free perovskites for next-generation functional devices.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Amorphous to crystalline transformation of BCZT films: a complex microstructure studied by synchrotron X-rays, ferro-electric, and optical spectroscopy

  • 期刊论文

  • 发表日期：

    2026年1月6日

查看全文
  • Dhanunjaya Munthala,
  • Akhil Raman,
  • Thita Sonklin,
  • Natthawadi Buatip,
  • Pimchanok Leuasoongnoen,
  • Pattanaphong Janphuang,
  • Supinaya Nijpanich,
  • Wanthana Klysubun,
  • Prae Chirawatkul,
  • V. L. Prasad Gumma,
  • K. C. James Raju,
  • Soodkhet Pojprapai

摘要

(Ba,Ca)(Zr,Ti)O3 (BCZT) is a lead-free perovskite oxide with promising applications in electronic, ferroelectric, and optoelectronic devices. Understanding its growth mechanisms and structure–property correlations in thin films is essential for device optimization. In this work, BCZT thin films were deposited via pulsed laser deposition (PLD) at substrate temperatures ranging from room temperature (RT) to 700 °C and systematically investigated to reveal their structural, chemical, microstructural, optical, and electrical evolution. Ti K-edge XANES showed distinct pre-edge peaks A (4968.6 eV) and B (4969.65 eV), corresponding to 1 s → 3d (t₂g) and 1 s → eg transitions, confirming enhanced octahedral symmetry, stronger Ti–O covalency, and a stable Ti4⁺ state (edge at 4979.5 eV) with increasing temperature. XPS analysis revealed a shift in film composition from Ba0.73Ca0.05Zr0.12Ti0.10O3 (pristine) to Ba0.51Ca0.08Zr0.11Ti0.30Oₓ after annealing at 700 °C, indicating Ba depletion, improved Ca incorporation, and increased Ti content, consistent with cation redistribution toward balanced perovskite stoichiometry. Grazing incidence X-ray diffraction (GI-XRD) confirmed amorphous growth below 600 °C, perovskite crystallization at 600 °C (crystallite size ~ 9.5 nm), and tetragonal polycrystallinity at 700 °C (7.0 nm) with reduced dislocation density (~ 1015 m⁻2). FE-SEM showed grain refinement from ~ 18 nm (RT) to ~ 10 nm (700 °C) with smoother surfaces. The ferroelectric studies revealed a clear evolution from paraelectric to well-defined ferroelectric behavior with increasing deposition temperature, with the 700 °C films exhibiting saturated, square P–E loops and high remanent polarization (~ 29.5 µC/cm2), confirming the formation of stable switchable domains.Optical studies revealed high visible transmittance (75–85%), a reduction in refractive index at 550 nm from 2.257 (RT) to 2.184 (700 °C), and film thickness decrease from 317 to 230 nm. The optical bandgap narrowed slightly from 3.93 to 3.82 eV, correlating with improved crystallinity and densification. Overall, this study highlights how deposition temperature governs the structural ordering, chemical stoichiometry, and optical response of BCZT thin films, providing insights for tailoring lead-free perovskites for next-generation functional devices.