|
Showing 1 - 4 of
4 matches in All Departments
Charles S. Sahagian Chief, Electromagnetic Materials Technology
Branch Deputy for Electronic Technology Hanscom AFB, MA 01731 I t
should not be surprising that an event as significant as the
discovery of the laser has had some con comitant impact on other
areas of science and technology, but the extent of the impact was
grossly unpredicted. Upon perusal of this bibliography, devoted to
the subject of laser window and mirror materials, it becomes very
apparent that the effect of the laser on materials R&D has been
enormous. Several hundred papers and reports, representing millions
of dollars of effort, have been promulgated over the past decade;
and as new frequencies, improved tunability, higher power, and
other charac teristics are achieved, we can expect even greater
demands and requirements on the materials com munity. What are some
of the highlights disclosec by this bibliography with regard to
work already ac complished? First, one can note the extensive
investigations into developing new materials while at the same time
improving old ones. Among the latter, alkali halides, for example,
have essentially had a rebirth. I n the past five years more
progress has been achieved in the chemical and structural perfec
tion of this class of materials than in the entire preceding
century. Also carried along in the surge for improved laser
materials have been the alkaline earth fluorides (prime candidates
for 3-to 5-J, Lm ap plications), chalcogenides, semiconductors,
oxides, and others."
Coverage This bibliography of over 5000 references is restricted to
the crystal growth of inorganic materials and is largely drawn from
the literature collection of the Research Materials Information
Center, although other sources were used in the attempt to attain
(an always unattainable) completeness. It includes theoretical,
review, and experimental, or "recipe," papers, technical reports,
and books. The period covered is from 1972 through 1977, with
several hundred more recent and earlier references, for var ious
reasons, added. (I nformation on specific materials not I isted may
be requested from R M C. ) I The coverage of epitaxy presented a
problem, since authors do not always make it clear whether or not
the epitaxial growth described resulted in single or
polycrystalline structures. Papers are of course included where
single crystallinity was claimed or illustrated by a definite
electron diffraction pattern. Stated attempts to grow single
crystals, even when failures, are included. As for the many where a
decision could not be made, exclusion was the general rule.
Theoretical and review papers are included. Two books, ofthe many
good books on crystal growth, are essential complements to this
bibliography: The Chemistry of Imperfect Crystals, 2nd Revised
Edition. Volume 1, Preparation, Purification, Crystal Growth and
Phase Theory Kroger, F. A. North-Holland Publishing Company,
Amsterdam-London; American Elsevier Publishing Company, Inc., New
York (1973) (Includes an extensive tabulation of crystals grown by
a variety of methods, with over 1100 references for the table
alone. ) Crystal Growth Wilke, K. -T."
Man's first experience with the ordered state of matter to which we
now apply the generic term "crystals" came about when he found
specimens of some of the natural crystalline mineral substances
that are re latively common in the surface and near-surface areas
of the earth's crust. His first widespread use of these natural
materials in which their crystalline nature was of importance was
undoubtedly in fabricating jewelry and otherwise adorning his
weapons, tools, and household items. Both the Old and New Testa
ments of the Bible document the use of crystalline gems, and the
Romans are credited with first employing diamonds-a metastable
crystalline form of carbon-in jewelry. Various civilizations appear
to have ascribed magical powers to some natural crystals, and they
are known to have been widely accepted in Europe as having
medicinal properties during the Middle Ages. Given early man's
appreciation of the symmetry and beauty of natural crystals, it is
not surprising that his earliest interest in working with these
materials appears to have been directed toward techniques for
duplicating or manufacturing these sub stances that were so highly
valued as gems. Although the exact beginning of the science that we
now know as "crystal growth" cannot be precisely specified, we do
know that Robert Boyle had attempted to grow crystals that could be
used as gems prior to 1672. Much later, in 1873, M. A."
|
You may like...
Ab Wheel
R209
R149
Discovery Miles 1 490
|