高压物理学报2022，Vol.36Issue(2)：9-16,8.DOI:10.11858/gywlxb.20210842
CaF2纳米晶粒结构相变行为的尺寸依赖性
Size-Dependent Structural Phase Transition Behaviors of CaF2 Nanocrystals
摘要
Abstract
CaF2 nanocrystals with a size of 11 nm have been investigated using X-ray diffraction technique under high pressure. A phase transition from the fluorite structure to the α-PbCl2-type structure has been observed at 12 GPa, which is much higher than the value observed in the bulk CaF2 and slightly lower than the one in smaller-sized CaF2 nanocrystals. The compressibility of the CaF2 nanocrystals is discussed, an obviously higher incompressibility than the bulk CaF2 is observed. The α-PbCl2-type metastable phase is retained when the pressure is released to ambient conditions. The unique high-pressure behaviors of the 11 nm-sized CaF2 nanocrystals are attributed to defects and grain size effect. The grain size effect is considered to be the main factor influencing the high-pressure behaviors of the CaF2 nanocrystals. When the size of the CaF2 nanocrystals is as small as 11 nm, the higher surface energy leads to the enhancement of the structural stability and the increase of the bulk modulus.关键词
高压/氟化钙纳米晶粒/相变/X射线衍射/尺寸效应Key words
high pressure/CaF2 nanocrystals/phase transition/X-ray diffraction/size effect分类
数理科学引用本文复制引用
巩蕾,王婧姝,张俊凯,陈广博,张晗,武晓鑫,胡廷静,崔航..CaF2纳米晶粒结构相变行为的尺寸依赖性[J].高压物理学报,2022,36(2):9-16,8.基金项目
National Natural Science Foundation of China (11904128) （11904128）
Thirteenth Five-Year Program for Science and Technology of Education Department of Jilin Province (JJKH20200410KJ) （JJKH20200410KJ）
Academic Graduate Students Scientific Research Innovation Fund of Jilin Normal University (202005) （202005）
