Download or read book Development of Hydrothermal Method for Growing Large High Purity Single Crystals of Beryllium Oxide and Lead Metaniobate Initiate Growing Single Crystals of Ktn written by V. G. Hill and published by . This book was released on 1965 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: Growth rate studies of BeO in 4N-KOH at 15,000 p.s.i. were conducted. The growth rate along the c-axis was found to increase from 0.004 inches per day at 550 C, to 0.014 inches per day at 700 C. The growth rate in the plane perpendicular to this was 0.002 inches per day. Many of the crystals were twinned along the polar axis, and this produced an apparent increase in growth rate since most of the growth occurred in the positive polar direction. A study of the subsolidus equilibrium relationships in systems of the type KNbO3-KTaO3-solution has shown that the results with KOH solutions weaker than 4 normal are not significantly different from the results using pure water. However, K2CO3 solutions produce two new phases, one stable below 300 C, and the other between 300 and 600 C. This suggests that attempts to grow KTN hydrothermally must be made above 600 C. (Author).

Download or read book Development of Hydrothermal Method for Growing Large High Purity Single Crystals of Beryllium Oxide and Initiate Research on Growing Single Crystals of Ktn and Chrysoberyl written by V. G. Hill and published by . This book was released on 1966 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrothermal growth studies of BeO in 4N-KOH solution were continued. When (00.1) oriented seeds are used the (10,0) faces which formed were well developed, but the resultant crystal had many inclusions and defects. The (10.1) cut seeds tend to give crystals of better quality. The crystals grown are being evaluated for purity by emission spectroscopy and the electron microprobe. The survey of possible hydrothermal solvents for the growth of KTN was continued, and KOH and K2CO3 solutions show good promise. Crystals measuring 1-2 mm have been grown from the former, in the temperature range 440-700 C at 15,000 psi, but they were not of the desired composition and were anisotropic. Work has been started on the hydrothermal growth of chrysoberyl.

Download or read book Technical Abstract Bulletin written by and published by . This book was released on with total page 776 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ferroelectric Materials and Ferroelectricity written by T. F. Connolly and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 692 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is a joint effort of the Research Materials Information Center (RMIC) of the Solid State Division at Oak Ridge National Laboratory and the Libraries and Information Systems Center at Bell Telephone Laboratories (BTL) Murray Hill, N. J. The Research Materials Information Center has, since 1963, been answering inquiries on the avail ability, preparation, and properties of inorganic solid-state research materials. The preparation of bibliographies has been essential to this function, and the interest in ferroelectrics led to the compila tion of the journal and report literature on that subject. The 1962 book Ferroelectric Crystals, by Jona and Shirane, was taken as a cutoff point, and all papers through mid-1969 received by the Center have been included. The Libraries and Information Systems Center of BTL has, over a period of years, developed a proprie tary package of computer programs called BELDEX, which formats and generates indexes to biblio graphic material. This group therefore undertook to process RMIC's ferroelectric references by BELDEX so that both laboratories could have the benefit of an indexed basic bibliography in this important research area.

Download or read book Hydrothermal Growth of Single Crystals written by Vincent G. Hill and published by . This book was released on 1968 with total page 69 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrothermal methods have been found feasible for the growth of single crystals of beryllium oxide, ruby and calcite. The study of ruby growth has been devoted to evaluating those factors which are the most significant in producing fault-free crystals. These include (1) removal from the seeds by etching all major defect areas, (2) a stable convection system, (3) growth from a solution more dilute than previously proposed, (4) avoidance of thermal shocking which can produce cracks, (5) a positioning of the seeds in the vessel far enough away from the sides and from each other to avoid the 'wall effect, ' and (6) selecting particular crystallographic orientations for the seed plates. Single crystals of beohmite (A10. OH) were produced which were of sufficient size for optical properties to be measured on them. The study of beryllium oxide was concentrated on methods to produce high quality seeds. The techniques explored involved (1) rocking autoclave, (2) flux transport, (3) flux evaporation and (4) spontaneous nucleation under hydrothermal conditions. The study of calcite was devoted to a determination of the solubilities in K2CO3. Solubilities ranged from essentially zero to over 25% in 2 to 6 normal solutions between 300 and 800C, and 20,000 to 60,000 p.s.i. (Author).

Download or read book Crystallization Processes under Hydrothermal Conditions written by A. N. Lobachev and published by Springer Science & Business Media. This book was released on 2013-03-08 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: This collection conta ins the results of a number of investiga tions which have been carried out in the Hydrothermal Synthesis Laboratory of the Institute of Crystallography, Academy of Sciences of the USSR; it constitutes a continuation of an earlier collection which appeared in 1968: Hydrothermal Synthesis of Crystals. Problems associated with the synthesis of oxides, simple and complex sulfides, carbonates, silicates, and germanates are consid ered, and a great deal of factual material relating to the growth of single crystals of some of these compounds on a seed is presented. Some of the articles pay special attention to the kinetic asp ect of the growth of crystals; the conditions of growth are relat ed to the morphological characteristics of the growing faces, and the relationship between the habit of the crystals and the oomposi tion and constitution of the solutions is considered. A fair number of articles are concerned with the crystalliza tion of new compounds, most of which have now been synthesized under hydrothermal conditions for the very first time; these in clude ternary chalcohalides of composition AVBvIVVII. zirconates, lithium silicates, and germanates. The collection also contains a description of the apparatus used for precision measurements at high temperatures and pres sures. We hope that this publication will present a better idea of the special characteristics of the hydrothermal method of synthes izing and .growing crystals, and will prove useful to all those in terested in this field of knowledge.

Download or read book Hydrothermal Synthesis of Crystals written by A. N. Lobachev and published by Springer. This book was released on 1971 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book HYDROTHERMAL GROWTH OF LARGE RUBY SINGLE CRYSTALS PHASE 1 written by and published by . This book was released on 1965 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt: Studies of the hydrothermal growth of ruby crystals involved solubility of Al2O3 in K2CO3 as a function of pressure (5,000 - 30,000 psi), temperature (400 - 600 C) and mineralizer content (2 - 7 m). The solubility of Al2O3 increased with increasing molality and temperature but was essentially independent of pressure. Solubilities of 2-9 WT% Al2O3 were observed under the preceding conditions. Growth rate increased with temperature and solvent concentration but exhibited a very rapid increase with pressure at about 15,000 psi. This was due apparently to a transition from a two-phase fluid below 15,000 psi to a single-phase fluid above this pressure. Growth of high quality crystals was found to be dependent upon seed source, seed orientation and warm-up procedure. The highest quality growth was obtained when molten salt plates were used as seeds. Conditions established for growth of good quality crystals at reasonable rate are: 6m K2CO3 as solvent, 25,000 psi, crystallization temperature 525 deg C and nutrient temperature 530 deg C. From crystals grown by these procedures, several rods were fabricated into laser rods.

Download or read book Physical Properties of Materials written by M. C. Lovell and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: Materials Science has now become established as a discipline in its own right as well as being of increasing importance in the fields of Physics, Chemistry and Engineering. To the student meeting this subject for the first time the combination of disciplines which it embraces represents a formidable challenge. He will require to understand the lan guage of the physicist and chemist as well as appreciate the practical uses and limita tions of solid materials. This book has been written as an introduction to the Physical Properties of Materials with these thoughts in mind. The mathematical content has been limited deliberately and emphasis is placed on providing a sound basis using simplified models. Once these are understood we feel that a mathematical approach is more readily assimilated and for this purpose supplementary reading is suggested. While the authors are deeply aware of the pitfalls in attempting such a treatment this is meant to be an essentially simple book to point the many avenues to be explored. We anticipate that the book will appeal to first and second year degree students in a variety of disciplines and may not prove too difficult for those studying appropriate Higher National Certificate and Diploma courses. Electrical engineers working in the field of materials applications may well find it useful as a guide to modern thinking about materials and their properties. The book begins with an introduction to some basic ideas of modern physics.

Download or read book Handbook of Hydrothermal Technology written by K. Byrappa and published by . This book was released on 2001 with total page 870 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experiments with the Bridgman Method for Growing Large Metal Crystals written by John Francis Burns and published by . This book was released on 1927 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Preparation of Single Crystals written by William Donald Lawson and published by . This book was released on 1960 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Preparation Techniques for Growth of Single Crystals of Nonmetallic Materials written by E. M. Clausen and published by . This book was released on 1963 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Techniques for growth of high-purity single crys tals of nonmetallic materials are to be developed. The two approaches are single-crystal growth by the Verneuil technique using an r-f coupled plasma of argon as a heat source and crystal growth by the floating zone technique. The heat source for the floating zone technique will be either an oxide susceptor, such as stabilized zirconia, or direct r-f coupling to the non metallic material. (Author).

Download or read book Apparatus for Growth of Single Crystal Single Domain LiNbO3 written by Robert M. Hilton and published by . This book was released on 1969 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: A Czochralski crystal growing furnace has been constructed and put into operation for the growth of single crystalline lithium niobate (LiNbO3). Procedure for the preparation of feed material is discussed. The associated annealing and poling techniques are described in detail. (Author).

Download or read book Research for Hydrothermal Growth of Single Crystals written by Vincent G. Hill and published by . This book was released on 1968 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: Work continued to throw light on the cause and effect relationships between growth and defects in hydrothermally formed crystals. Several hydrothermal rubies grown under conditions where good quality crystals were usually obtained were either cracked, contained local areas of abundant tiny inclusions, or colored yellow. Further work has established that thermal shock is the major factor responsible for the cracks. The inclusions are due to what may be described as the 'wall effect', and the yellow color to the particle size of the gold inclusion. The modification of the process to correct these defects has resulted in the growth of crystals of greatly improved quality. (Author).

Download or read book A Method for Growing Single Crystals of Metals written by Ralph Edmund Herzler and published by . This book was released on 1940 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Research to Optimize Growth Techniques for Single Crystals written by George N. Webb and published by . This book was released on 1974 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: The synthesis from the elements of various high purity semiconductor materials of the Group II-VI compound type is discussed. A description of the pressure furnace system used for melting these compounds is given. The growth of crystals of pure II-VI compounds from the melt using this pressure furnace system is reported. In particular, melt crystal growth programs of ZnS, ZnSe, CdS, CdSe, and ZnTe are defined, including the results of special doping attempts on some of these crystals. It is concluded that the crystal growth processes described herein are practical for use with II-VI compound semiconductor materials. They are particularly recommended for the uniform doping of crystals.