Scholarlink

<p>This investigation explores the structural and dielectric modifications in sol-gel-synthesized LaFe₁₋ₓNiₓO₃ nanoparticles (x = 0, 0.1, 0.3, 0.5) through Ni doping. All compositions crystallize predominantly in an orthorhombic structure with the Pbnm space group, confirming minimal secondary phases. Ni incorporation induces lattice distortions, evidenced by peak broadening and shifts in XRD patterns, consistent with ionic radius differences between Fe³⁺ (0.645 Å) and Ni²⁺ (0.69 Å). FESEM reveals homogeneous nanoparticle distributions with an average size of 30&#xa0;nm, aligning with crystallite size trends observed in Ni-doped LaFeO₃ systems. UV-Vis Diffuse Reflectance: Ni doping broadens absorption spectra and reduces optical bandgap energies, attributed to intermediate energy states from Ni²⁺/Ni³⁺ and oxygen vacancies. Raman Spectroscopy: Phonon mode shifts confirm structural distortions, particularly in Fe/Ni-O bond dynamics, influencing oxygen mobility and lattice disorder. XPS: Surface analysis reveals Ni predominantly occupies Fe sites, altering oxidation states and enhancing surface charge interactions, which correlate with dielectric responses. Non-Debye Relaxation: Nyquist plots indicate a dominant grain boundary contribution at higher Ni concentrations and temperatures, accepted by electrical modulus spectra. The activation energy values of the grain boundary and grain for x = 0.1, x = 0.3, and x = 0.5 are 0.21&#xa0;eV and 0.180&#xa0;eV, 0.172&#xa0;eV, 0.191&#xa0;eV, and 0.144&#xa0;eV, 0.134&#xa0;eV, respectively. Activation energy decreases with Ni content, suggesting enhanced N-type polaronic hopping due to Ni-induced defect states. Frequency-dependent conductivity implies the Jonscher power law, while the Jump Relaxation Model explains localized hopping of charge carriers.</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

Nickel-doped LaFeO3 nano particles with n-type polaronic hopping conduction through intra-grain boundary and grain effect

  • 期刊论文

  • 发表日期：

    2025年9月8日

查看全文
  • T. Lakshmana Rao,
  • S. Dash

摘要

This investigation explores the structural and dielectric modifications in sol-gel-synthesized LaFe₁₋ₓNiₓO₃ nanoparticles (x = 0, 0.1, 0.3, 0.5) through Ni doping. All compositions crystallize predominantly in an orthorhombic structure with the Pbnm space group, confirming minimal secondary phases. Ni incorporation induces lattice distortions, evidenced by peak broadening and shifts in XRD patterns, consistent with ionic radius differences between Fe³⁺ (0.645 Å) and Ni²⁺ (0.69 Å). FESEM reveals homogeneous nanoparticle distributions with an average size of 30 nm, aligning with crystallite size trends observed in Ni-doped LaFeO₃ systems. UV-Vis Diffuse Reflectance: Ni doping broadens absorption spectra and reduces optical bandgap energies, attributed to intermediate energy states from Ni²⁺/Ni³⁺ and oxygen vacancies. Raman Spectroscopy: Phonon mode shifts confirm structural distortions, particularly in Fe/Ni-O bond dynamics, influencing oxygen mobility and lattice disorder. XPS: Surface analysis reveals Ni predominantly occupies Fe sites, altering oxidation states and enhancing surface charge interactions, which correlate with dielectric responses. Non-Debye Relaxation: Nyquist plots indicate a dominant grain boundary contribution at higher Ni concentrations and temperatures, accepted by electrical modulus spectra. The activation energy values of the grain boundary and grain for x = 0.1, x = 0.3, and x = 0.5 are 0.21 eV and 0.180 eV, 0.172 eV, 0.191 eV, and 0.144 eV, 0.134 eV, respectively. Activation energy decreases with Ni content, suggesting enhanced N-type polaronic hopping due to Ni-induced defect states. Frequency-dependent conductivity implies the Jonscher power law, while the Jump Relaxation Model explains localized hopping of charge carriers.