A fiveling, also known as a decahedral nanoparticle, a multiply-twinned particle (MTP), a pentagonal nanoparticle, a pentatwin, or a five-fold twin is a type of twinned crystal that can exist at sizes ranging from nanometers to millimetres. It contains five different single crystals arranged around a common axis. In most cases each unit has a face centered cubic (fcc) arrangement of the atoms, although they are also known for other types of crystal structure.
They nucleate at quite small sizes in the nanometer range, but can be grown much larger. They have been found in mineral crystals[a] excavated from mines such as pentagonite[2] or native gold from Ukraine,[3] in rods of metals grown via electrochemical processes and in nanoparticles produced by the condensation of metals either onto substrates or in inert gases. They have been investigated for their potential uses in areas such as improving the efficiency of solar cell or heterogeneous catalysis for more efficient production of chemicals. Information about them is distributed across a diverse range of scientific disciplines, mainly chemistry, materials science, mineralogy, nanomaterials and physics. Because many different names have been used, sometimes the information in the different disciplines or within any one discipline is fragmented and overlapping.
At small sizes in the nanometer range, up to millimetres in size, with fcc metals they often have a combination of {111} and {100} facets, a low energy shape called a Marks decahedron.[4][5] Relative to a single crystal, at small sizes a fiveling can be a lower energy structure due to having more low energy surface facets.[b] Balancing this there is an energy cost due to elastic strains to close an angular gap (disclination), which makes them higher in energy at larger sizes. They can be the most stable structure in some intermediate sizes, but they can be one among many in a population of different structures due to a combination of coexisting nanoparticles and kinetic growth factors. The temperature, gas environment and chemisorption can play an important role in both their thermodynamic stability and growth. While they are often symmetric, they can also be asymmetric with the disclination not in the center of the particle.
- ^ Jang, Ji-Hoon; Lee, Eunjik; Park, Jinwoo; Kim, Gunn; Hong, Suklyun; Kwon, Young-Uk (2013). "Rational syntheses of core-shell Fex@Pt nanoparticles for the study of electrocatalytic oxygen reduction reaction". Scientific Reports. 3 (1): 2872. doi:10.1038/srep02872. ISSN 2045-2322. PMC 3791448. PMID 24096587.
- ^ Cite error: The named reference
:6was invoked but never defined (see the help page). - ^ Kvasnifsa, V. N.; Kuznetsov, Yu. A.; Latysh, I. K. (1981). "Crystal morphology of native gold from some ore regions of the Ukraine". International Geology Review. 23 (2): 227–232 Figure 5. Bibcode:1981IGRv...23..227K. doi:10.1080/00206818209467235. ISSN 0020-6814.
- ^ Cite error: The named reference
:7was invoked but never defined (see the help page). - ^ Doye, Jonathan (1996). "The Structure, Thermodynamics and Dynamics of Atomic Clusters". doye.chem.ox.ac.uk. Retrieved 9 May 2024.
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