Ultrafine Metal Particles Formed by Gas-Evaporation Technique. II. Crystal Habits of Magnesium, Manganese, Beryllium and Tellurium

Nanoparticles can be beautiful, as in stained glass windows, or they can be ugly as in wear and corrosion debris from implants. We estimate that there will be about 70,000 papers in 2015 with nanoparticles as a keyword, but only one in thirteen uses the nanoparticle shape as an additional keyword and research focus, and only one in two hundred has thermodynamics. Methods for synthesizing nanoparticles have exploded over the last decade, but our understanding of how and why they take their forms has not progressed as fast. This topical review attempts to take a critical snapshot of the current understanding, focusing more on methods to predict than a purely synthetic or descriptive approach. We look at models and themes which are largely independent of the exact synthetic method whether it is deposition, gas-phase condensation, solution based or hydrothermal synthesis. Elements are old dating back to the beginning of the 20th century-some of the pioneering models developed then are still relevant today. Others are newer, a merging of older concepts such as kinetic-Wulff constructions with methods to understand minimum energy shapes for particles with twins. Overall we find that while there are still many unknowns, the broad framework of understanding and predicting the structure of nanoparticles via diverse Wulff constructions, either thermodynamic, local minima or kinetic has been exceedingly successful. However, the field is still developing and there remain many unknowns and new avenues for research, a few of these being suggested towards the end of the review.

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“…literature [49][50][51][52][53][54][55] as well as earlier structural studies on colloidal growth [56,57].…”

Section: Introductionmentioning

confidence: 88%

Nanoparticle shape, thermodynamics and kinetics

Marks

Peng

2016

J. Phys.: Condens. Matter

246

274

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“…It may be worth mentioning that the hexagonal arrangement of nanoparticles seems more pronounced when the diffraction peaks of YbN are detected and the 311 and 400 peaks were clearly observed, though the details for this are still unknown. The growth of various fcc material nanoparticles has been studied in many works [29,30,14,16,17]. Hayashi et al [17] studied the formation of ultrafine metal particles by the gas-evaporation technique.…”

Section: Hexagonal Structuresmentioning

confidence: 99%

“…In the present study, we have employed a completely different technique, the gas deposition method, which uses a similar set-up for vacuum evaporation but the principle is very different. The technique can be used for the preparation of various kinds of fine metallic particles [12][13][14][15][16][17][18][19][20]. It has to be noted that up to now there have been no published reports on Yb particles obtained by the gas deposition route except the authors' preliminary works [20,28].…”

Section: Introductionmentioning

confidence: 99%

Structures of Yb nanoparticle thin films grown by deposition in He and N₂gas atmospheres: AFM and x-ray reflectivity studies

Jerab

Sakurai

2010

J. Phys.: Condens. Matter

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Nanoparticles of lanthanide metals and their compounds are important from the viewpoint of both basic research and application to many functional devices. In the present work, a gas deposition technique was employed to prepare thin films composed of ytterbium (Z = 70) nanoparticles on a glass substrate. The influence of deposition conditions such as deposition temperature, time and gas pressure was studied in detail. In addition to an ordinary inert gas such as He, the possible use of N(2) was investigated. As a result of combined analysis using atomic force microscopy (AFM) and x-ray reflectivity, it was found that spherical nanoparticles of around 1-140 nm in diameter can be obtained upon deposition in both He and N(2) atmospheres. The thin film is not amorphous but fcc crystals of metallic ytterbium with a small amount of hcp phase are mainly formed. When exposed to air, the top surface is covered by an oxide layer due to natural oxidation. The thickness and density were in the range of 5-30 nm and 4-9 g cm(-3), respectively, depending on the deposition conditions. As only small amounts of nitrides were formed during deposition in an N(2) atmosphere in many cases, it was concluded that the use of N(2) can be a feasible alternative to the ordinary gas deposition method with an inert gas. Finally, some self-organized hexagonally shaped structures, which are more frequently observed upon deposition in N(2), are reported.

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“…Typical production methods of clusters and ultrafine particles are laser vaporization, oven, and gas evaporation, which have been developed by Smalley and co-workers [30], Recknagel and co-workers [31], and Uyeda and co-workers [32], respectively. However, these production methods are not particularly suited to produce and analyze large and annealed clusters of various kinds.…”

Section: Introductionmentioning

confidence: 99%

Production and characterization of thermally-annealed large clusters by high-pressure laser-vaporization technique

Sugai

Shinohara

1997

Z Phys D - Atoms, Molecules and Clusters

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We have developed a high-pressure laser-vaporization cluster source, which enables us to produce large, annealed clusters. Large carbon clusters up to C + 2000 , annealed sodium fluoride clusters of Na + (NaF) n , and ammonium iodide clusters of NH + 4 (NH 4 I) n have been produced by this technique. Annealed ammonium iodide clusters show a transition from hydrogen bonded complexes to ionic crystals as the cluster size increases. The characterization of the present technique and the production processes of the large, annealed clusters are discussed.

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Ultrafine Metal Particles Formed by Gas-Evaporation Technique. II. Crystal Habits of Magnesium, Manganese, Beryllium and Tellurium

Cited by 67 publications

References 3 publications

Nanoparticle shape, thermodynamics and kinetics

Nanoparticle shape, thermodynamics and kinetics

Structures of Yb nanoparticle thin films grown by deposition in He and N₂gas atmospheres: AFM and x-ray reflectivity studies

Production and characterization of thermally-annealed large clusters by high-pressure laser-vaporization technique

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Ultrafine Metal Particles Formed by Gas-Evaporation Technique. II. Crystal Habits of Magnesium, Manganese, Beryllium and Tellurium

Cited by 67 publications

References 3 publications

Nanoparticle shape, thermodynamics and kinetics

Nanoparticle shape, thermodynamics and kinetics

Structures of Yb nanoparticle thin films grown by deposition in He and N2gas atmospheres: AFM and x-ray reflectivity studies

Production and characterization of thermally-annealed large clusters by high-pressure laser-vaporization technique

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Product

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Structures of Yb nanoparticle thin films grown by deposition in He and N₂gas atmospheres: AFM and x-ray reflectivity studies