Frontiers in Crystalline Matter From Discovery to Technology (2009) / Chapter Skim
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Appendix D: Synthesis Techniques
Appendix D: Synthesis Techniques
Pages 157-168
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From page 157... ...
Floating-Zone Growth of Oxide Crystals Oxide crystals are grown by a wide spectrum of techniques, including crystal pulling by Czochralski (CZ) or Bridgman methods, flux growth, top-seeded solution growth, and others.
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From page 158... ...
While flux methods are more efficient for explor ing a complex compositional phase space, FZ crystal growth is the best and most generally applicable growth method when large, high-purity crystals of known materials are required. In many cases, crystals of cubic centimeter volumes can be routinely grown.
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From page 159... ...
Proof of principle that feedback systems can be used in this mode to control dopant distribution effec tively has already been demonstrated for laser-heated pedestal growth of Cr-doped LaAlO3. Extension of this approach to more complex oxides utilizing the FZ technique will effectively allow for phase-diagram studies in a single growth experiment.
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From page 160... ...
The solution growth technique has been used to grow single crystals of virtually every class of materials, including elements, intermetallics, oxides, chalcogenides, and organic compounds (Figure D.2)
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From page 161... ...
With an expanded number of practitioners, with improved, simplified, and automated methods of growth and nucleation control, and with the availability of expanded chemical and physical phases, solution growth will be one of the frontline methods for growing crystals of new materials that will be the creative engines that drive basic and applied research for the next century. Crystal Growth by Vapor Transport For materials with volatile components, the growth of crystals from a vapor phase is often an important technique that is frequently employed to make crystals for fundamental property studies.
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From page 162... ...
Although establishing the basic parameters of the growth process and identi fying the best transport agents have constituted a field of significant study in past years, the technique itself has not recently been subject to concentrated study. As with other crystal growth methods, further development of the vapor growth FIGURE D.3 A crystal of cobalt chloride boracite grown by vapor transport.
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From page 163... ...
Small crystals of the "heavy fermion oxide" LiV2O4 have been grown hydrothermally in recent years in a Japanese academic research laboratory, but the use of this method to grow crystals for the study of basic condensed-matter physics in an academic setting is very rare. Although the hydrothermal growth method has seen relatively limited use outside industrial science programs, a related method, called solvothermal growth, does see wide application in academic solid-state chemistry laboratories.
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From page 164... ...
A large variety of techniques exist for growing crystalline thin films, including molecular-beam epitaxy (MBE) , evaporation, sputtering, chemi cal vapor deposition, and laser ablation.
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From page 165... ...
Because of the strong hybridization of oxygen p orbitals and transition metal d orbitals, oxides display a wider variety of strongly correlated behavior at room temperature than do covalently bonded semiconductors. The strongly coupled charge, spin, orbital, electronic, and lattice degrees of freedom offer the promise of novel functionality in thin-film devices, provided growth processes in oxides can be mastered.
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From page 166... ...
Advances in the growth of heterostructures, espe cially the complex oxides, demands the immediate development of new approaches to in situ probes of the growth processes including the surface/interface structure, chemistry, and electronic structure. A deposition system that allows in situ probing of growth processes is in place at the Spring-8 beam line in Japan, where pre liminary experiments have already been reported; some progress toward this has been made in the United States at the Advanced Photon Source (see Figure D.5)
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From page 167... ...
A chemical vapor deposition process that has within it the inherent Key Scientificorder parameters abilityQuestions:atomic-layer control � Coupling of for orbital lattice (as manifested in an atomic-layer deposition process) isconversion Ferroelectricity and magnetism desirable -- such � Energy extremely Spiral � Perovskite a process does not currently exist.
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From page 168... ...
. E pitaxial constraints in three dimensions play a key role in the formation of such nanostructures, as well as enabling strong magnetoelectric coupling between the two phases.
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