Based on large-scale density functional theory calculations we provide a systematic overview of the size dependence of the energetic order and magnetic properties of various morphologies of FePt and CoPt clusters with diameters of up to 2.5 nm. For FePt, ordered multiply twinned icosahedra and decahedra are more favorable than the L1_(0) phase throughout the investigated size range. For CoPt, segregated morphologies predominate with considerably increased energy differences to the L1_(0) structure. The compositional trends are traced back to differences between the morphologies in the partial electronic density of states associated with the 3d element.
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http://dx.doi.org/10.1103/PhysRevLett.100.087203 | DOI Listing |
Nanoscale
December 2024
Laboratoire MONARIS, UMR 8233, Sorbonne Université, 4 Place Jussieu, 75005 Paris, France.
Precise tuning of ligands and a comprehensive understanding of their roles and functionalities are crucial for the design of nanoparticles (NPs) with tailored properties. In this study, we present the synthesis of copper NPs with precise control over their shape and crystallinity, relying on the remarkable versatility of oleylamine (OLA) as both a solvent and a ligand. By adjusting the temperature, OLA enables the formation of cubic NPs under rapid heating, reflecting kinetic control, and octahedral NPs with slow heating, indicating thermodynamic control.
View Article and Find Full Text PDFJ Phys Chem A
October 2024
Department of Chemistry, College of Natural Science, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea.
This Review provides the first comprehensive overview of the structure and properties of exotic -crystalline aperiodic cyclic multiply twinned nano- (10-100 ) and meso- (up to 1 ) diamond particles (MTPs) exhibiting pentagonal symmetry. It spans their independent experimental discoveries (1963, 1964, 1972, and 1983) and theoretical structural insights (1993) to recent advancements. The Review focuses on high-symmetry MTPs formed by the fusion of multiple cubic diamond fragments through [111] facets.
View Article and Find Full Text PDFNano Lett
April 2024
Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, Ciudad de México, Mexico 04510.
Given the binary nature of nanoalloy systems, their properties are dependent on their size, shape, structure, composition, and chemical ordering. When energy and entropic factors for shapes and structure variations are considered in nanoparticle growth, the spectra of shapes become so vast that even metastable arrangements have been reported under ambient conditions. Experimental and theoretical variations of multiply twinned particles have been observed, from the Ino and Marks decahedra to polyicosahedra and polydecahedra with comparable energetic stability among them.
View Article and Find Full Text PDFJ Am Chem Soc
January 2024
Department of Physics, Technical University of Denmark, 2800 Kongens Lyngby, Denmark.
Understanding the size-dependent behavior of nanoparticles is crucial for optimizing catalytic performance. We investigate the differences in selectivity of size-selected gold nanoparticles for CO electroreduction with sizes ranging from 1.5 to 6.
View Article and Find Full Text PDFJ Am Chem Soc
December 2023
Department of Chemistry, Rice University, MS 6000, Main Street, Houston, Texas 77005, United States.
Seed-mediated syntheses rely on small nanoparticle (NP) precursors that act as templates for growth but are often inhomogeneous with respect to their internal twinning structures (e.g., single crystalline, multiply twinned), leading to nonuniform product morphologies.
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