Mechanical property and irradiation resistance of high entropy pyrochlore (Sm0.2Eu0.2Gd0.2Y0.2Lu0.2)2Ti2O7

• Published in: Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms Vol. 533; pp. 17 - 22
• Main Authors: Wang, Hao, Zhu, Changzu, Wang, Zezhen, Wang, Menghui, Li, Yuhong
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.12.2022
• Subjects: High entropy pyrochlore; Immobilization material; Irradiation resistance; Vickers hardness; High entropy pyrochlore; Vickers hardness; Irradiation resistance; Immobilization material
• ISSN: 0168-583X; 1872-9584
• DOI: 10.1016/j.nimb.2022.10.011

•We apply concept of high-entropy pyrochlore to simultaneously solidify multiple radionuclides.•High-entropy pyrochlore exhibits good mechanical property possibly attributed to lattice distortion.•The irradiation result shows high-entropy pyrochlore has good radiation resistance.•Raman analysis confirms that high-entropy pyrochlore has serious lattice distortion. High entropy ceramics have recently attracted a lot of attention due to their superior physical properties. In this work, a novel high entropy pyrochlore (Lu0.2Y0.2Gd0.2Eu0.2Sm0.2)2Ti2O7 (HTP-1) was designed and prepared. Sample was characterized by X-ray diffraction, Raman spectroscopy and transmission electron microscopy coupled with an energy dispersive spectrometry. The results show that single-phase HTP-1 is successfully synthesized and exhibits severe lattice distortion. The Vickers hardness of HTP-1 measured by the microhardness tester is ∼ 922.28 Hv, which is significantly higher than the result calculated with the mixture rule, demonstrating that high entropy pyrochlore has high mechanical hardness. In-situ TEM was performed on HTP-1 irradiated with 800 keV Kr2+ at room temperature to investigate irradiation resistance of sample. The critical amorphization dose of HTP-1 is 0.27 dpa, which indicates the irradiation resistance of HTP-1 is between Sm2Ti2O7 and Y2Ti2O7.