无机功能晶体材料的结晶过程研究

功能晶体材料作为光、声、电等转换的重要介质,已经被广泛应用于能源、信息、航空航天等高新技术领域,是目前国际材料科学与工程学科发展的热点和前沿课题.结晶过程是制备功能材料的核心环节,结晶习性直接影响材料的光、电、磁、催化等功能特性.在无机材料的结晶过程中,晶体组成在微观上经历了从自由态离子到结晶态固体的相变过程.可以借助晶体组成离子的电负性及基团微观对称性的变化,研究结晶过程中聚集体的形成和结构演变规律.利用分子振动光谱能够从分子尺度上揭示非线性光学晶体材料在水溶液结晶过程中结晶学结构的形成过程,克服了传统原位观测手段中缺乏对非长程有序结构的确定.利用结晶生长的化学键合理论从热力学和动力学两个方面指导大块晶体的生长实践,合理调控晶体的生长表/界面热力学和动力学.将结晶生长的化学键合理论应用到大尺寸晶体提拉生长参数的设计和优化,成功搭建了大尺寸晶体智能生长系统,并成功生长了φ2″蓝宝石晶体、φ3″YAG晶体和φ4″铌酸锂晶体.

Study on the crystallization process of function inorganic crystal materials

Functional crystal materials used as the important conversion media of light, sound and electricity, have been widely applied to high-tech fields such as energy, information, aerospace and related hot topics at the forefront of materials science and engineering subject. Crystallization process is the core of the preparation of functional materials, crystal growth habit of materials directly affects the functional performances of optical, electrical, magnetic, and catalytic behaviors. During the crystallization process of inorganic materials, crystals are microscopically transformed from free-state ions into the crystalline solid-phase. We can use the ionic electronegativity and microscopic symmetry changes of constituent components, to study the crystallization process of aggregation formation and structure evolution. Using molecular vibration spectroscopy we can at the molecular scale, reveal the crystallization process of nonlinear optical crystal materials in aqueous solution crystallization process, to overcome the lack of traditional means of in situ observations determining those non-long-range order structures. Chemical bonding theory of single crystal growth can from both thermodynamic and kinetic aspects of the whole system, effectively guide the growth of large crystals, reasonably regulate the growth surface and interface thermodynamics and kinetics. The chemical bonding theory of single crystal growth is applied to the design and optimization of growth parameters of large-size crystal pulling growth system, we have built up a large-size crystal growth system, and successfully grown φ2″ sapphire crystals, φ3″ YAG crystals, and φ4″ lithium niobate crystals.