Scholarlink

<p>Copper sulfide-based thermoelectric materials composed of earth-abundant and environmentally benign elements have attracted considerable attention for mid-temperature energy conversion. Bornite (Cu<sub>5</sub>FeS<sub>4</sub>), a p-type semiconductor with intrinsically low lattice thermal conductivity, is considered a promising candidate for applications in the 300–700&#xa0;K temperature range. However, achieving phase-pure bornite with optimized transport properties remains challenging due to its sensitivity to processing conditions and phase stability. In this study, we systematically investigate the effect of hot pressing (HP) temperature on phase evolution, microstructure, and thermoelectric transport properties of bornite synthesized via mechanical alloying (MA). Particular emphasis is placed on understanding the relationship between phase purity, secondary phase suppression, and transport behavior. X-ray diffraction analysis reveals that secondary chalcopyrite (CuFeS<sub>2</sub>) phases form at lower HP temperatures (623–673&#xa0;K), while a phase-pure bornite is obtained at 723&#xa0;K, indicating that sufficient thermal energy is required for complete phase homogenization. This phase evolution is found to strongly influence both charge and thermal transport properties. Although the electrical conductivity decreases slightly with increasing HP temperature, the reduction in thermal conductivity and improved phase homogeneity lead to enhanced thermoelectric performance. The sample processed at 723&#xa0;K exhibits the lowest thermal conductivity (&lt; 0.5&#xa0;W m⁻¹ K⁻¹) and achieves the highest figure of merit, with a maximum ZT of 0.65 at 723&#xa0;K. These results demonstrate that precise control of HP conditions is critical for suppressing secondary phases and optimizing the balance between electrical and thermal transport, providing a practical strategy for improving the performance of bornite-based thermoelectric materials.</p> Graphic Abstract <p></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

Bornite Cu5FeS4: Solid-State Synthesis and Thermoelectric Properties

  • 期刊论文

  • 发表日期：

    2026年6月20日

查看全文
  • Hyeon-Sik O,
  • Il-Ho Kim

摘要

Copper sulfide-based thermoelectric materials composed of earth-abundant and environmentally benign elements have attracted considerable attention for mid-temperature energy conversion. Bornite (Cu5FeS4), a p-type semiconductor with intrinsically low lattice thermal conductivity, is considered a promising candidate for applications in the 300–700 K temperature range. However, achieving phase-pure bornite with optimized transport properties remains challenging due to its sensitivity to processing conditions and phase stability. In this study, we systematically investigate the effect of hot pressing (HP) temperature on phase evolution, microstructure, and thermoelectric transport properties of bornite synthesized via mechanical alloying (MA). Particular emphasis is placed on understanding the relationship between phase purity, secondary phase suppression, and transport behavior. X-ray diffraction analysis reveals that secondary chalcopyrite (CuFeS2) phases form at lower HP temperatures (623–673 K), while a phase-pure bornite is obtained at 723 K, indicating that sufficient thermal energy is required for complete phase homogenization. This phase evolution is found to strongly influence both charge and thermal transport properties. Although the electrical conductivity decreases slightly with increasing HP temperature, the reduction in thermal conductivity and improved phase homogeneity lead to enhanced thermoelectric performance. The sample processed at 723 K exhibits the lowest thermal conductivity (< 0.5 W m⁻¹ K⁻¹) and achieves the highest figure of merit, with a maximum ZT of 0.65 at 723 K. These results demonstrate that precise control of HP conditions is critical for suppressing secondary phases and optimizing the balance between electrical and thermal transport, providing a practical strategy for improving the performance of bornite-based thermoelectric materials.

Graphic Abstract