Anandkumar Mariappan, Kesavan Kannan Pidugu, Sudarsan Shanmugavel, Zhivulin Dmitry Evgenievich, Shaburova Natalia Aleksandrovna, Ostovari Moghaddam Ahmad, Litvinyuk Ksenia Sergeevna, Trofimov Evgeny Alekseevich
High-Entropy Materials Research Laboratory, South Ural State University, Chelyabinsk 454080, Russia.
Department of Physics, PSG Institute of Technology and Applied Research, Coimbatore 641 062, India.
Nanomaterials (Basel). 2025 Jun 17;15(12):939. doi: 10.3390/nano15120939.
High-entropy ceramics have gained wider attention due to their structural integrity and stability, which can be used in various functional applications. Especially, high-entropy oxides exhibit excellent thermal stability, particularly at high temperatures. Thermal barrier coating materials must demonstrate good thermal stability without any phase transformation or phase separation, which is critical in aerospace and energy conversion applications. To address this, we have prepared new high-entropy stannate pyrochlore oxide nanoparticles with the composition (GdNdLaPrSm)SnO through a simple glycine-assisted sol-gel synthesis. The phase evolution was probed at different heat-treatment temperatures from 1000 °C to 1500 °C. Among the temperatures investigated, a single-phase pyrochlore oxide was formed from 1300 °C without any impurity or phase separation. The obtained nanoparticles were characterized using various techniques, including X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), nanoindentation, and dilatometry to investigate their physiochemical and mechanical properties. The Vickers hardness of high-entropy oxides is 4.2 ± 0.33 GPa, while a thermal expansion coefficient (TEC) of 8.7 × 10 K at 900 °C is calculated. The results show that the prepared high-entropy pyrochlore oxide can be a suitable candidate for thermal barrier coating.
高熵陶瓷因其结构完整性和稳定性而受到更广泛关注，可用于各种功能应用。特别是，高熵氧化物表现出优异的热稳定性，尤其是在高温下。热障涂层材料必须表现出良好的热稳定性，且无任何相变或相分离，这在航空航天和能量转换应用中至关重要。为解决这一问题，我们通过简单的甘氨酸辅助溶胶-凝胶合成法制备了组成为(GdNdLaPrSm)SnO的新型高熵锡酸盐焦绿石氧化物纳米颗粒。在1000℃至1500℃的不同热处理温度下探究了相演变。在所研究的温度中，从1300℃开始形成单相焦绿石氧化物，无任何杂质或相分离。使用包括X射线衍射(XRD)、场发射扫描电子显微镜(FESEM)、纳米压痕和热膨胀测量法等各种技术对所得纳米颗粒进行了表征，以研究其物理化学和机械性能。高熵氧化物的维氏硬度为4.2±0.33 GPa，在900℃时计算出的热膨胀系数(TEC)为8.7×10 K。结果表明，所制备的高熵焦绿石氧化物可成为热障涂层的合适候选材料。
