International Journal of Engineering and Techniques - Volume 3 Issue 5, Sep - Oct 2017

RESEARCH ARTICLE OPEN ACCESS

Introduction to Crystal Growth Techniques
1
B.Subashini , 2Mrs.Geetha
1
M.Phil Research Scholar, 2Asst.Professor in Chemistry
Department of Chemistry, Prist University, Puducherry, India

Abstract:
Man had admired crystals for long, as he had appreciated their beauty. The gems and crystals delivered by mother
earth have always attracted our mankind, and the belief in the virtues of gems and some minerals dates back to at least
two thousand years. The use of gems for ornamental purposes appears to be in practice since the birth of
humankind. Today, crystals are the pillars of modern technology. Without crystals, there would be no electronics
industry, no photonics industry, no fibre-optic communications, very little modern optical equipment and some very
important gaps in conventional production engineering. In the past few decades, there has been a growing interest in
crystal growth process, particularly in view of the increasing demand of materials for technological applications
(Laudise 1975; Brice1986; Nalwa and Miyata 1996).
The significance of crystal growth to electrical engineering, chemistry and physics is illustrated in Figure 1.1.
Modern technology requires physicists, chemists, electrical engineers, metallurgists and crystal growers to assist
each other at many levels. Crystal growth is a vital and fundamental part of materials science and engineering, since
crystals of suitable size and perfection are required for fundamental data acquisition and for practical devices such as
detectors, integrated circuits and for other applications.

Keywords — crystals, L-histidine, nonlinear optics, second harmonic generation, Barium nitrate.

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 International Journal of Engineering and Techniques - Volume 3 Issue 5, Sep - Oct 2017

Figure 1.1 Significance of crystal growth to electrical engineering, chemistry and physics

Progress in crystal growth is highly demanded in view of its recent advancements in

the fields of semiconductors, polarizer’s, transducers, infrared detectors, ultrasonic
amplifiers, ferrites, magnetic garnets, solid state lasers, nonlinear optic, piezoelectric,
acousto-optic, photosensitive materials and crystalline thin films for microelectronics and
computer industries. The utility of crystals has been extended from the bounds of ornaments
to several useful applications in optical, electrical and optoelectronic devices. The fantasy of
their external beauty was understood more thoroughly through the natural laws of
mathematics, physics and chemistry. The contents of the crystals and their insides were
explored, analyzed and understood by modern methods of diffraction as well as with the help
of spectroscopic techniques. The external shapes, planes and colours were correlated with the
internal atomic content and their arrangements in unequivocal terms. Thus grew a science,
the study of “crystal growth and characterization”.

Introduction: and Scheel (1975) on high temperature

Methods of Crystal Growth: solution growth.
Growth of crystal ranges from a small The basic common principle in all
inexpensive technique to a complex these methods is that a nucleus is first formed,
sophisticated expensive process and and it grows into a single crystal by
crystallization time ranges from minutes, organizing and assembling ions or molecules
hours, days and to months. The starting points with specific interactions and bonding, so that
are the historical works of the inventors of the process is slow and multiple nucleations is
several important crystal growth techniques minimized. Crystal growth process and size of
and their original aim. The methods of the grown crystal differ widely and are
growing crystals are very wide and mainly determined by the characteristics of the
dictated by the characteristics of the material material. An efficient process is the one,
and its size (Buckley 1951; Mullin 1976). which produces crystals adequate for their use
The methods of growing single at minimum cost. The growth method is
crystals may be classified according to their essential because it suggests the possible
phase transformation as given below. impurity and other defect concentrations.
Choosing the best method to grow a given
Growth from solid Solid solid phase material depends on material characteristics.
transformation Growth from Solution
Growth from liquid Liquid solid phase The crystal growth from liquid can
transformation be classified into six categories
Growth from vapor Vapor solid phase namely,
transformation (i) Melt growth
The above methods have been (ii) High temperature solution
discussed in detail by several authors (Brice growth (Flux growth)
1986; Pamplin 1980; Chernov 1984). The (iii) Hydrothermal growth
different techniques of each category are (iv) Gel growth
found in reviews and books by Factor and (v) Electrocrystallization and
Garret (1974) on vapour growth, Brice (1973) (vi) Low temperature solution
on melt, Henisch (1988) on gel growth, growth
Buckley (1951) on solution growth and Elwell There are number of growth methods

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 International Journal of Engineering and Techniques - Volume 3 Issue 5, Sep - Oct 2017

in each category. Among various methods of a suitable solvent and crystallization occurs as
growing single crystals, solution growth at low the solution becomes critically supersaturated.
temperature occupies a prominent place owing The supersaturation may be promoted by
to its versatility and simplicity. Growth from evaporation of the solvent, by cooling the
solution occurs close to equilibrium conditions solution or by a transport process in which
and hence crystals of perfection can be grown. the solute is made to flow from a hotter to a
Study of anisotropy of the properties of cooler region. The high temperature crystal
crystals requires specimens cut in different growth can be divided into two major
orientations from the same single crystal. categories: first one is growth from single
This can be easily done from crystals of large component systems and the second one is that
size. from multi-components. In this method, a
Growth from melt solid (molten salt/flux) is used as the solvent
Melt Growth is the process of instead of liquid and the growth takes place
crystallization by fusion and resolidification of well below the melting point (Hubner 1969) of
the pure material. In this technique apart from the solute. The success of crystal growth from
possible contamination from crucible materials high temperature solution largely depends on
and surrounding atmosphere, no impurities are the selection of the solvent system.
introduced in the growth process and the rate This technique can be used for the
of growth is normally much higher than that crystallization of oxide compounds which
possible by other methods. Mainly for the generally have high melting points as well
latter reason, melt growth is commercially the as for materials which have phase
most important method of crystal growth. The transitions below the melting point
preferential role of the electrochemical process (Ramachandra Raja et al 1993). The crystals
responsible for the change in composition of grown from melt have lower concentration of
the crystals when they grow in melt in an equilibrium defects and lower dislocation
applied field has been studied (Balasanyan et density. One major disadvantage of this
al1990). The growth from melt can further be method is the corrosive nature of the fluxes
sub-grouped into various techniques. used, which attack the common furnace
The main techniques are: materials.
Bridgman Technique Hydrothermal growth
Czochralski Technique The term hydrothermal means,
Zone melting Technique literally, “hotwater”. But in the jargon of the
Verneuil Technique crystal grower, hydrothermal also implies
Heat exchanger Method conditions of high pressure as well as high
Skull melting and temperature. Closely related to growth from
Shaped crystal growth aqueous solution at ambient or near-ambient
conditions is growth from hydrothermal
The major practical factors to be considered
solution. Hydrothermal growth is usually
during growth of crystals from melt are, (a)
defined as the use of an aqueous solvent at
volatility, (b) the chemical reactivity and (c)
elevated temperature and pressure to
the melting point.
dissolve a solute which would ordinarily
High temperature growth (Flux growth) be virtually insoluble at ambient
Flux and hydrothermal growths
conditions. The disadvantages of the
form the category of high temperature
hydrothermal techniques are mainly associated
solution growth. In the growth of crystals from
with high pressure and inability to observe
high-temperature solutions, the constituents of
growth during the process. Quartz is the
the material to be crystallized are dissolved in

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 International Journal of Engineering and Techniques - Volume 3 Issue 5, Sep - Oct 2017

crystal grown industrially by this technique. crystal growth. The method of crystal growth
from low temperature aqueous solutions is
Gel growth extremely popular in the production of many
The growth of variety of crystals technologically important crystals. The growth
having immense importance for their of crystals by low temperature solution growth
practical consideration and theoretical involves weeks, months and sometimes years.
interest has been achieved by gel technique Much attention has been paid to understand
(Henisch 1988). The importance of the gel the growth mechanism of the process.
growth is attributed to its simplicity in Materials having moderate to high
technique, effectiveness in growing single solubility in temperature range, ambient to
crystals of compounds that cannot easily be 100 oC at atmospheric pressure can be grown
grown by other methods. Though the origin of by low temperature solution growth method.
the method dates back to 1899 – the famous This method is the most widely used method
work of Liesegang who discovered the for the growth of single crystals, when the
periodic crystallization in gels, interest in gel starting materials are unstable at high
technique received attention only after the temperature (Pamplin 1979). This method is
work of Henisch and his co-workers (Henisch widely used to grow bulk crystals, which have
1970; Henisch 1988; Henisch and Garcia-Ruiz high solubility and have variation in solubility
1986). Crystal growth in gels is a with temperature (James and Kell 1975;
promising technique for growing single crystals Chernov 1984). Growth of crystals from
of substances which are slightly soluble in solution at room temperature has many
water and which cannot be grown conveniently advantages over other growth methods
from melt or vapour. The gel method has also though the rate of crystallization is slow.
been applied to study the crystal formation in Since growth is carried out at room
urinary calculi and rheumatic diseases. temperature, the structural imperfections in
Electrocrystallization solution grown crystals are relatively low
Electrocrystallization is the basis for (Brice 1972). The low temperature solution
important fields such as corrosion, energy growth technique also allows variety of
storage and generation, electrodeposition, different morphologies and polymorphic forms
electronics material development, of the same substance, which can be grown by
electrorefining and electrotwinning etc. variations of growth conditions or of solvent.
Crystallization without chemical The proximity to ambient temperature reduces
transformation or charge transfer is the the possibility of major thermal shock to the
simplest case. In certain instances, the crystal both during growth and on removal
crystallization is determined by a chemical from the apparatus.
transformation occurring prior to or The main disadvantages of the low
simultaneously with the crystallization temperature solution growth are the slow
process. The part played by the chemical growth rate in many cases and the ease of
reaction is to supply the material, which solvent inclusion into the growing crystal.
crystallizes. Electrocrystallization is the Under the controlled conditions of growth, the
process, which leads to the formation of a solvent inclusion can be minimized and the
new face at the electrode/electrolyte high quality of the grown crystal can
interface, which in turn plays a major role. compensate the disadvantage of much longer
Low temperature solution growth growth periods. After undergoing so many
Growth of crystals from aqueous modification and refinements, the process of
solution is one of the ancient methods of solution growth now yields good quality

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 International Journal of Engineering and Techniques - Volume 3 Issue 5, Sep - Oct 2017

crystals for a variety of applications. 2011, accepted 23 December 2011)

Low temperature slution growth can be
subdivided into the following methods:
(i) Slow cooling method
(ii) Slow evaporation method and
(iii) Temperature gradient method
Conclusion:
Solution preparation and crystal growth
For solution preparation, it is essential
to have the solubility data of the material at
different temperatures. Sintered glass filters
of different pore size are used for solution
filtration. The clear solution, saturated at the
desired temperature is taken in a growth
vessel. For growth by slow cooling, the vessel
is sealed to prevent the solvent evaporation.
Solvent evaporation at constant temperature
can be achieved by providing a controlled
vapour leak. A small crystal suspended in the
solution is used to test the saturation. By
varying the temperature, a situation where
neither the occurrence of growth nor
dissolution is established.
The test seed is replaced with a
good quality seed. All unwanted nuclei and
the surface damage on the seed are removed
by dissolving at a temperature above the
saturation point. Growth is initiated after
saturation. Solvent evaporation can also be
helpful in initiating the growth. The quality of
the grown crystal depends on the (a) nature
of seed, (b) cooling rate employed and (c)
agitation of the solution.
Reference:-
1. Crystal Growth and its applications and
non linear optics(NLO)–An
Introductionshodhganga.inflibnet.ac.inbi
tstream10603104761010_chapter1
2. Shodhganga.inflibnet.ac.in/bitstream/10603/
33423/4/chapter%201
3. S. Suresh and D. Arivuoli Optical and
conductivity properties of L-Histidine
Nitrate
4. NLO single crystal (Received 17 September

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