Scholarlink

<p>This study explored in detail the structural, conduction mechanisms, dielectric, and optical characteristics of two perovskites La<sub>0.5</sub>Ca<sub>0.5</sub>CrO<sub>3</sub> (LCCO) and La<sub>0.5</sub>Sr<sub>0.5</sub>CrO<sub>3</sub> (LSCO) prepared via sol–gel method. The X-ray diffraction analysis indicated a pure phase with no additional phases present in our samples. The investigation of electrical conductivity revealed semiconductor behavior in the specimens, aligning with the Non-Overlapping Small Polaron Tunneling (NSPT) model. Besides, the LCCO and LSCO have a high electrical resistivity (<i>ρ</i> ~ 2.10<sup>8</sup> Ω.m), which make the samples potential for microwave device applications. Subsequently, it was found that LSCO sample has lower activation energy (<i>E</i><sub>a</sub> = 0.153&#xa0;eV) compared to the sample LCCO (<i>E</i><sub>a</sub> = 0.166&#xa0;eV). These findings suggest that Sr and Ca ions substitution reduces activation energies, enhancing electrical conductivity and dielectric characteristics of the LaCrO<sub>3</sub> (LCO) samples. Further, the band gap energy (<i>E</i><sub>g</sub>) declines from 2.52&#xa0;eV for LCCO to 2.34&#xa0;eV for LSCO sample. These values are lower than the obtained values for the undoped LCO sample. It is apparent that the incorporation of Ca and Sr ions in LCO sample clearly lowers its band gap energy, which improved its optoelectronic properties. The provided <i>λ</i><sub>T</sub> values range from 484&#xa0;nm for LCCO to 473&#xa0;nm for LSCO sample. The lower threshold wavelengths are often associated with lower band gap energies. This implies that when trying to carry out optoelectronic activities, the specimen needs photons with a higher energy (lower wavelength).</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

Study of La0.5R0.5CrO3 (R = Ca, Sr) ceramics: rietveld analysis, charge transfer mechanism, band gap energies, and optical properties for advanced multifunctional applications

  • 期刊论文

  • 发表日期：

    2025年5月28日

查看全文
  • Fakher Hcini,
  • H. Kaouach,
  • Jabeur Khelifi,
  • Kamel Khirouni

摘要

This study explored in detail the structural, conduction mechanisms, dielectric, and optical characteristics of two perovskites La0.5Ca0.5CrO3 (LCCO) and La0.5Sr0.5CrO3 (LSCO) prepared via sol–gel method. The X-ray diffraction analysis indicated a pure phase with no additional phases present in our samples. The investigation of electrical conductivity revealed semiconductor behavior in the specimens, aligning with the Non-Overlapping Small Polaron Tunneling (NSPT) model. Besides, the LCCO and LSCO have a high electrical resistivity (ρ ~ 2.108 Ω.m), which make the samples potential for microwave device applications. Subsequently, it was found that LSCO sample has lower activation energy (Ea = 0.153 eV) compared to the sample LCCO (Ea = 0.166 eV). These findings suggest that Sr and Ca ions substitution reduces activation energies, enhancing electrical conductivity and dielectric characteristics of the LaCrO3 (LCO) samples. Further, the band gap energy (Eg) declines from 2.52 eV for LCCO to 2.34 eV for LSCO sample. These values are lower than the obtained values for the undoped LCO sample. It is apparent that the incorporation of Ca and Sr ions in LCO sample clearly lowers its band gap energy, which improved its optoelectronic properties. The provided λT values range from 484 nm for LCCO to 473 nm for LSCO sample. The lower threshold wavelengths are often associated with lower band gap energies. This implies that when trying to carry out optoelectronic activities, the specimen needs photons with a higher energy (lower wavelength).