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Nanosensor Laboratory
Published in Vinod Kumar Khanna, Nanosensors, 2021
The F-Z process entails the passing of a molten zone through a polysilicon rod that has approximately the same dimensions as the final ingot. A polycrystalline rod is passed through an radio-frequency (RF) heating coil, creating a localized molten zone from which the crystal ingot is grown. A seed crystal (a small piece of single-crystal material, from which a large crystal of the same material is typically grown) is used at one end to initiate the growth process. The purity of an ingot produced by the F-Z process is higher than that produced by the C-Z process. These impurities are mainly introduced by the material of the crucible (a refractory container used for metal, glass, etc., production), which holds the silicon melt. As such, C-Z silicon has much higher oxygen and carbon impurities than does F-Z silicon.
Processing of Optical Materials
Published in Solomon Musikant, Optical Materials, 2020
The crystallographic orientation of the crystal so grown can be controlled by the orientation of the seed crystal. Sapphire boules having diameters up to 4 in. are made in this manner and are commercially available.
Research on effect of seed crystal on piezoelectric effect characteristics in quartz wafer
Published in Australian Journal of Mechanical Engineering, 2022
Jun Zhang, Yu Han, Zongjin Ren, Jun Shao, Bing Wang, Zhenyuan Jia
A seed crystal is a small crystal having the same crystal orientation as a desired crystal and is a seed for growing crystals, which is also called seed of crystal. Seeding with seed crystals of different crystal orientations will grow crystals of different crystal orientations. Sometimes seed crystal remains after the crystal is cut into wafers, so the seed wafer contains a different seed ribbon than pure wafer, as shown in Figure 1. The surface of the sample is mirrored after being polished, and the existence of grain boundaries and other defects are not observed except for the holes generated during sample processing and scratches and very few holes generated during polishing. The polished seed crystal wafer image taken by the optical microscope (the magnification of eyepiece is 10×) shows that the size of seed crystal in the wafer is larger than that of ordinary wafer.
Solid state crystal growth of single crystals of 0.75(Na1/2Bi1/2)TiO3-0.25SrTiO3 and their characteristic electrical properties
Published in Journal of Asian Ceramic Societies, 2021
Phan Gia Le, Thuy Linh Pham, Dang Thanh Nguyen, Jong-Sook Lee, John G. Fisher, Hwang-Pill Kim, Wook Jo
In the present work, the solid state crystal growth technique is used to grow single crystals [40,41]. In this technique, a piece of single crystal (the seed crystal) is buried inside the polycrystalline powder of the composition to be grown, pressed into a pellet and then sintered. A single crystal with the same composition as the powder grows epitaxially on the seed crystal. The relatively low processing temperature (lower than the melting point of the compound to be grown) helps the single crystal preserve its stoichiometry and chemical homogeneity. Solid state crystal growth has been used to grow single crystals with properties comparable to those of conventionally-grown crystals. Single crystals of (Na1/2Bi1/2)TiO3-BaTiO3, (Na1/2Bi1/2)TiO3-Ba(Ti,Zr)O3, (Na1/2Bi1/2)TiO3-CaTiO3, (Na1/2Bi1/2)TiO3-SrTiO3 and (Na1/2Bi1/2)TiO3-BaTiO3-(K0.5N0.5)NbO3 have been grown by this technique [13,15,33,38,42–45]. In the present work, single crystals of 75 mol % (Na1/2Bi1/2)TiO3 – 25 mol % SrTiO3 (NBT-25ST) are grown by solid state crystal growth and the microstructure, structure and electrical properties of the grown single crystals are studied. Single crystals of NBT-25ST are found to have significantly improved inverse piezoelectric properties over their ceramic counterparts.