Abstract

The effect of strong stoichiometry violations in the structural type of fluorite (CaF₂) on the microhardness of Ba_0.9R_0.1F_2.1 (R = rare-earth elements La–Lu) crystals is studied. The mechanical hardening of heterovalent solid solutions Ba_0.9R_0.1F_2.1 as compared to the BaF₂ matrix is due to the formation of nanosized clusters of point defects [Ba₈R₆F₆₉] substituting structural fragments [Ba₁₄F₆₄] (block-type isomorphism). The microhardness of nanostructured Ba_0.9R_0.1F_2.1 crystals is found to increase by 73% as the cluster size decreases from [Ba₈La₆F₆₉] to [Ba₈Lu₆F₆₉].

中文翻译：

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纳米结构Ba 0.9 R 0.1 F 2.1（R =稀土元素）晶体的机械硬化：尺寸效应

摘要

研究了萤石（CaF ₂）的结构类型对化学计量的强烈违反对Ba _0.9 R _0.1 F _2.1（R =稀土元素La-Lu）晶体的显微硬度的影响。与BaF ₂基质相比，异价固溶体Ba _0.9 R _0.1 F _2.1的机械硬化是由于形成了点缺陷[Ba ₈ R ₆ F ₆₉ ]的纳米簇，取代了结构碎片[Ba ₁₄ F ₆₄ ]（嵌段型同构）。纳米结构Ba _0.9 R _0.1的显微硬度随着团簇尺寸从[Ba ₈ La ₆ F ₆₉ ]减小到[Ba ₈ Lu ₆ F ₆₉ ]，发现F _2.1晶体增加了73％。