Ryu Jaejong, Kim Il-Ho
Department of Materials Science and Engineering, College of Engineering, Korea National University of Transportation, Chungju 27469, Republic of Korea.
Materials (Basel). 2025 Mar 2;18(5):1129. doi: 10.3390/ma18051129.
Eskebornite (CuFeSe) is a I-III-VI semiconductor with a tetragonal crystal structure, known for its intriguing electrical and magnetic properties. However, experimental studies on this material remain scarce. In this study, Ni-doped eskebornite, CuNiFeSe (x = 0.02-0.06), was synthesized via solid-state methods by substituting Ni for Cu. Mechanical alloying was employed to prepare the compounds, followed by hot pressing. X-ray diffraction analysis revealed the eskebornite phase alongside a minor secondary phase, identified as penroseite (NiSe) with a cubic crystal structure. Thermoelectric properties were measured over the temperature range of 323-623 K. The Seebeck coefficient exhibited p-type behavior at low temperatures but transitioned to n-type at higher temperatures, indicating a temperature-dependent p-n transition due to changes in the dominant charge carriers. With increasing Ni doping, the Seebeck coefficient increased positively at low temperatures and negatively at high temperatures, with the p-n transition temperature shifting to lower values. Electrical conductivity decreased with higher Ni doping levels, while its positive temperature dependence became more pronounced, reflecting non-degenerate semiconductor behavior. Thermal conductivity showed a negative temperature dependence but increased with higher Ni content. The highest thermoelectric performance was observed for CuNiFeSe, achieving ZT = 0.30 × 10 at 523 K, and for CuNiFeSe, achieving ZT = 0.55 × 10 at 623 K, where ZT and ZT represent the dimensionless figure of merit for p-type and n-type thermoelectric materials, respectively.
埃斯凯硼镍矿（CuFeSe）是一种具有四方晶体结构的I-III-VI族半导体，以其有趣的电学和磁学性质而闻名。然而，对这种材料的实验研究仍然很少。在本研究中，通过用Ni替代Cu的固态方法合成了Ni掺杂的埃斯凯硼镍矿CuNiFeSe（x = 0.02 - 0.06）。采用机械合金化制备化合物，随后进行热压。X射线衍射分析表明，除了一个次要的次生相外，还存在埃斯凯硼镍矿相，该次生相被鉴定为具有立方晶体结构的彭罗斯矿（NiSe）。在323 - 623 K的温度范围内测量了热电性能。塞贝克系数在低温下表现出p型行为，但在较高温度下转变为n型，这表明由于主要载流子的变化导致了温度依赖性的p - n转变。随着Ni掺杂量的增加，塞贝克系数在低温下呈正向增加，在高温下呈负向增加，p - n转变温度向更低的值移动。电导率随着Ni掺杂水平的提高而降低，而其正温度依赖性变得更加明显，这反映了非简并半导体行为。热导率表现出负温度依赖性，但随着Ni含量的增加而增加。对于CuNiFeSe，在523 K时实现了ZT = 0.30×10，对于CuNiFeSe，在623 K时实现了ZT = 0.55×10，其中ZT和ZT分别代表p型和n型热电材料的无量纲品质因数。
