Wave-transparent materials are widely used as integrated structural-functional materials in various aircraft communication systems. However, the lack of high-performance wave-transparent materials has impeded the advancement of hypersonic aircraft. Consequently, the search for novel high-performance wave-transparent materials has become a critical challenge. This study investigates the dielectric, mechanical, and thermal properties of RE2Sn2O7 (RE = La, Nd, Sm, Eu, Gd, Tb, Dy, Er, and Lu) using both theoretical predictions and experimental measurements to evaluate their suitability as wave-transparent materials. Preliminary first-principles calculations predict exceptional mechanical properties for RE₂Sn₂O₇. These predictions are confirmed experimentally, with synthesized RE₂Sn₂O₇ samples exhibiting Young's modulus exceeding 200 GPa and hardness greater than 10 GPa. Additionally, they also present low dielectric constants (∼8) and dielectric loss tangent values below 0.01 with the dielectric constant unaffected by RE species, while the dielectric loss tangent value decreases as the RE³⁺ ionic radius decreases. Their thermal expansion coefficients range between of 8 × 10−6 K−1 and 10 × 10−6 K−1, while thermal conductivities can be as low as 2 W m⁻1 K⁻1. The relationship between RE³⁺ ionic radius and intrinsic properties is elucidated, revealing that a smaller ionic radius reduces dielectric loss tangent value while enhancing Young's modulus, hardness, and thermal expansion coefficient. These results provide valuable theoretical guidance for design of high-performance wave-transparent materials.

中文翻译：

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稀土锡酸盐：一种通过理论和实验方法研究的新型高性能透波材料


透波材料被广泛用作各种飞机通信系统中的集成结构功能材料。然而，高性能透波材料的缺乏阻碍了高超音速飞行器的发展。因此，寻找新型高性能透波材料已成为一项关键挑战。本研究使用理论预测和实验测量研究了 RE2Sn2O7 （RE = La、Nd、Sm、Eu、Gd、Tb、Dy、Er 和 Lu） 的介电、机械和热性能，以评估它们作为波透明材料的适用性。初步的第一性原理计算预测了 RE₂Sn₂O₇ 的优异机械性能。这些预测通过实验得到了证实，合成的 RE₂Sn₂O₇ 样品表现出杨氏模量超过 200 GPa，硬度大于 10 GPa。此外，它们还具有低介电常数 （∼8） 和低于 0.01 的介电损耗角正切值，介电常数不受 RE 物质的影响，而介电损耗角正切值随着 RE³⁺ 离子半径的减小而减小。它们的热膨胀系数在 8 × 10-6 K-1 和 10 × 10-6 K-1 之间，而导热系数可低至 2 W m⁻1 K⁻1。阐明了 RE³⁺ 离子半径与本征性质之间的关系，揭示了较小的离子半径会降低介电损耗角正切值，同时提高杨氏模量、硬度和热膨胀系数。这些结果为高性能透波材料的设计提供了有价值的理论指导。