Influence of synthesis process on the structural and microstructural behavior of neodymium doped sodium and potassium niobate powders

New synthesis process to prepare nano-particles of lithium niobate, sodium niobate and potassium niobate by thermal decomposition of the constituent double metal alkoxides was developed. Single crystals of such double-metal alkoxides as Na-Nb, Li-Nb and K-Nb ethoxides were newly synthesized from a mixed solution of the constituent metal ethoxides. The doublemetal alkoxides of the Li-Nb, Na-Nb and K-Nb systems decomposed at low temperatures below 673 K to form nano-particles of LiNbO3, NaNbO3 and LiNbO3. The lattice constants and crystallite size of the obtained LiNbO3, NaNbO3 and LiNbO3 particles were elucidated. It was shown that this new synthesis process was useful for preparation of niobate nano-particles at low temperatures.

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TEM study of phosphorus-implanted pseudomorphic Si0.88Ge0.12 on Si(100)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100138713 ◽

1995 ◽

Vol 53 ◽

pp. 468-469

Author(s):

N. David Theodore ◽

Donald Y.C Lie ◽

J. H. Song ◽

Peter Crozier

Keyword(s):

Integrated Circuits ◽

Heterojunction Bipolar Transistors ◽

Integrated Circuit ◽

High Speed ◽

Room Temperature ◽

Strain Relaxation ◽

Bipolar Transistors ◽

Sige Hbt ◽

Integrated Circuit Manufacturing ◽

Microstructural Behavior

SiGe is being extensively investigated for use in heterojunction bipolar-transistors (HBT) and high-speed integrated circuits. The material offers adjustable bandgaps, improved carrier mobilities over Si homostructures, and compatibility with Si-based integrated-circuit manufacturing. SiGe HBT performance can be improved by increasing the base-doping or by widening the base link-region by ion implantation. A problem that arises however is that implantation can enhance strain-relaxation of SiGe/Si.Furthermore, once misfit or threading dislocations result, the defects can give rise to recombination-generation in depletion regions of semiconductor devices. It is of relevance therefore to study the damage and anneal behavior of implanted SiGe layers. The present study investigates the microstructural behavior of phosphorus implanted pseudomorphic metastable Si0.88Ge0.12 films on silicon, exposed to various anneals.Metastable pseudomorphic Si0.88Ge0.12 films were grown ~265 nm thick on a silicon wafer by molecular-beam epitaxy. Pieces of this wafer were then implanted at room temperature with 100 keV phosphorus ions to a dose of 1.5×1015 cm-2.

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Characterization of a monolayer graphitic structure

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100171535 ◽

1994 ◽

Vol 52 ◽

pp. 760-761

Author(s):

X. Lin ◽

X. K. Wang ◽

V. P. Dravid ◽

J. B. Ketterson ◽

R. P. H. Chang

Keyword(s):

Three Dimensional ◽

Single Layer ◽

Synthesis Process ◽

Graphitic Structure ◽

Positive Gaussian Curvature ◽

Graphitic Sheet ◽

Structural And Electronic Properties ◽

New Material ◽

Hexagonal Network

For small curvatures of a graphitic sheet, carbon atoms can maintain their preferred sp2 bonding while allowing the sheet to have various three-dimensional geometries, which may have exotic structural and electronic properties. In addition the fivefold rings will lead to a positive Gaussian curvature in the hexagonal network, and the sevenfold rings cause a negative one. By combining these sevenfold and fivefold rings with sixfold rings, it is possible to construct complicated carbon sp2 networks. Because it is much easier to introduce pentagons and heptagons into the single-layer hexagonal network than into the multilayer network, the complicated morphologies would be more common in the single-layer graphite structures. In this contribution, we report the observation and characterization of a new material of monolayer graphitic structure by electron diffraction, HREM, EELS.The synthesis process used in this study is reported early. We utilized a composite anode of graphite and copper for arc evaporation in helium.

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