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Formation Mechanisms of Platelet Sr 3 Ti 2 O 7 Crystals Synthesized by the Molten Salt Synthesis Method
Author(s) -
Liu Yunfei,
Lu Yig,
Xu Ming,
Zhoun Liufei
Publication year - 2007
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2007.01706.x
Subject(s) - nucleation , crystallography , crystal growth , dissolution , crystal (programming language) , transmission electron microscopy , materials science , molten salt , electron diffraction , crystal structure , ion , mineralogy , diffraction , chemistry , nanotechnology , metallurgy , optics , computer science , programming language , physics , organic chemistry
The molten salt synthesis (MSS) method is utilized to synthesize the anisotropic platelet Sr 3 Ti 2 O 7 (S3T2) single‐crystal particles. The aim of this study is to identify the essence of platelet Sr 3 Ti 2 O 7 crystal growth and guide the synthesis of anisotropic platelet SrTiO 3 crystals as well as various technologically important materials. Based on the results of X‐ray diffraction, scanning electron microscopy, and high‐resolution transmission electron microscopy, the formation mechanism of platelet Sr 3 Ti 2 O 7 crystals conforms to a nucleation–structure rearrangement–dissolution–diffusion in situ epitaxial growth mechanism model. First, SrCO 3 reacts with TiO 2 to form submicrometer SrTiO 3 nuclei. Then, most of the nuclei surrounded by salt ions aggregate and rearrange to form a large SrTiO 3 matrix. The structural rearrangement and the subsequent in situ epitaxial growth processes control the morphology, composition, and size of the final Sr 3 Ti 2 O 7 crystals. In the synthesis process, the conversion between SrTiO 3 and Sr 3 Ti 2 O 7 is as follows:and the crystallographic orientation relationship between Sr 3 Ti 2 O 7 and SrTiO 3 in the interface is (100) S3T2 //{100} ST , (010) S3T2 //{010} ST , and (001) S3T2 //{001} ST .