Scholarlink

<p>Sm-doped nickel ferrite nanoparticles (NiFe<sub>2–x</sub>Sm<sub>x</sub>O<sub>4</sub>, x = 0, 0.025, 0.05, and 0.075) were synthesized via a simple co-precipitation method without any organic gelling agent. Thermogravimetric analysis (TGA) confirmed 800&#xa0;°C as the appropriate calcination temperature for achieving a stable spinel phase. Powder X-ray diffraction (PXRD), supported by Rietveld refinement, revealed the formation of a single-phase cubic spinel structure, with Sm<sup>3+</sup> substitution inducing lattice expansion, increased microstrain, and a reduction in the crystallite size (27–53&#xa0;nm). These structural changes were further evidenced by FT-IR and Raman spectroscopy, which indicated distortions in the metal–oxygen bonding environment due to Sm<sup>3+</sup> substitution at the octahedral B-sites. Optical measurements showed that Sm-doping enhanced visible-light absorption and narrowed the direct band gap from 1.67&#xa0;eV (undoped) to 1.58&#xa0;eV (x = 0.075), which was attributed to electronic interactions and lattice distortions. Magnetic characterization revealed that undoped and Sm-doped NiFe<sub>2</sub>O<sub>4</sub> nanoparticles are soft magnetic materials, with magnetic parameters decreasing with increasing Sm<sup>3+</sup> content, attributed to cation redistribution, weakened superexchange interactions, and minor secondary phases at higher doping levels. Overall, this study introduces the first synthesis of Sm-doped NiFe<sub>2</sub>O<sub>4</sub> nanoparticles via a simple, surfactant-free co-precipitation method, enabling precise low-level doping and single-phase spinel formation. The resulting narrowed band gap and enhanced magnetic softness suggest these materials as promising candidates for visible-light photocatalysis and soft-magnetic applications.</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

Tuning structural, optical, and magnetic properties of NiFe2O4 nanoparticles via low-level Sm3+ substitution by co-precipitation

  • 期刊论文

  • 发表日期：

    2026年2月26日

查看全文
  • Tan Khiem Nguyen,
  • Thu Trang Ly Thi,
  • Khai Dang Nguyen Nhu,
  • Vu Anh Thi Ngoc,
  • Xuan Vuong Bui,
  • Hong Diem Chau,
  • Anh Tien Nguyen

摘要

Sm-doped nickel ferrite nanoparticles (NiFe2–xSmxO4, x = 0, 0.025, 0.05, and 0.075) were synthesized via a simple co-precipitation method without any organic gelling agent. Thermogravimetric analysis (TGA) confirmed 800 °C as the appropriate calcination temperature for achieving a stable spinel phase. Powder X-ray diffraction (PXRD), supported by Rietveld refinement, revealed the formation of a single-phase cubic spinel structure, with Sm3+ substitution inducing lattice expansion, increased microstrain, and a reduction in the crystallite size (27–53 nm). These structural changes were further evidenced by FT-IR and Raman spectroscopy, which indicated distortions in the metal–oxygen bonding environment due to Sm3+ substitution at the octahedral B-sites. Optical measurements showed that Sm-doping enhanced visible-light absorption and narrowed the direct band gap from 1.67 eV (undoped) to 1.58 eV (x = 0.075), which was attributed to electronic interactions and lattice distortions. Magnetic characterization revealed that undoped and Sm-doped NiFe2O4 nanoparticles are soft magnetic materials, with magnetic parameters decreasing with increasing Sm3+ content, attributed to cation redistribution, weakened superexchange interactions, and minor secondary phases at higher doping levels. Overall, this study introduces the first synthesis of Sm-doped NiFe2O4 nanoparticles via a simple, surfactant-free co-precipitation method, enabling precise low-level doping and single-phase spinel formation. The resulting narrowed band gap and enhanced magnetic softness suggest these materials as promising candidates for visible-light photocatalysis and soft-magnetic applications.