【摘 要】
：
Sapphire,belonging to hexagonal crystal system,is typically anisotropic which makes it direction-sensitive.To research the effects of growth directions on properties of sapphire,c-[0001]seed(c-sapphire)and a-[11-20]seed(a-sapphire)were used to prepare sap
【机 构】
：
College of Material Science and Technology,Nanjing University of Aeronautics and Astronautics,Nanjin
【出 处】
：
武汉理工大学学报（材料科学版）（英文版）
论文部分内容阅读
Sapphire,belonging to hexagonal crystal system,is typically anisotropic which makes it direction-sensitive.To research the effects of growth directions on properties of sapphire,c-[0001]seed(c-sapphire)and a-[11-20]seed(a-sapphire)were used to prepare sapphire by edge-defined film-fed growth(EFG)method.The samples were analyzed through lattice integrity,dislocation and corrosion performance by double-crystal XRD,OM,AFM,SEM and EDX.It was shown that the lattice integrities of two growth-direction crystals were both well due to the small FWHM values.While the average densities of dislocation in c-sapphire and a-sapphire were 9.2×10 3 and 3.9×10 3 cm-2 respectively,the energy of dislocation in c-sapphire was lower than that in a-sapphire.During Strong Phosphoric Acid(SPA)etching,the surface of c-sapphire basically kept smooth but in a-sapphire there were many point-like corrosion pits where aluminum and oxygen atoms lost by 2:1.Our work means that it will be promising for growing c-[0001]seed sapphire by EFG if aided by parameter optimization.
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