More Like this

1. Widely Varying Kondo and Magnetic Interactions in Molecule Gold Nanostructured Materials by Changing the Gold Nanoarchitecture

   https://doi.org/10.1021/acs.nanolett.2c04918  

   Tie, Monique ; Colford, Sean ; Niewczas, Marek ; Baumbach, Ryan ; Dhirani, Al-Amin ( January 2023 , Nano Letters)

   Delocalized−localized electron interactions are central to strongly correlated electron phenomena. Here, we study the Kondo effect, a prototypical strongly correlated phenomena, in a tunable fashion using gold nanostructures (nanoparticle, NP, and nanoshell, NS) + molecule cross-linkers (butanedithiol, BDT). NP films exhibit hallmark signatures of the Kondo effect, including (1) a log temperature resistance upturn as temperature decreases in a metallic regime, and (2) zero-bias conductance peaks (ZBCPs) that are well fit by a Frota function near a percolation insulator transition, previously used to model Kondo peaks observed using tunnel junctions. Remarkably, NP + NS films exhibit ZBCPs that persist to >220 K, i.e., >10-fold higher than that in NP films. Magnetic measurements reveal that moments in NP powders align, and in NS powders, they antialign at low temperatures. Based on these observations, we propose a mechanism in which varying such material nanobuilding blocks can modify electron−electron interactions to such a large degree. 

   more » « less
2. Orogenic gold ores in three-dimensions: A case study of distinct mineralization styles at the world-class Cuiabá deposit, Brazil, using high-resolution X-ray computed tomography on gold particles

   https://doi.org/10.1016/j.oregeorev.2021.104584  

   Ferraz da Costa, Marília ; Kyle, J. Richard ; Lobato, Lydia M. ; Ketcham, Richard A. ; Figueiredo e Silva, Rosaline C. ; Fernandes, Raphael C. ( January 2022 , Ore Geology Reviews)
3. Design and fabrication of pH-responsive monodisperse gold/peptide/gold sandwich nanoparticles

   https://doi.org/10.1016/j.mfglet.2023.03.003  

   Li, Wei ; Zhang, Zimeng ; Liu, Yuchen ; Qiu, Jingjing ; Wang, Shiren ( July 2023 , Manufacturing Letters)
4. Organometallic gold nanoparticles and thin films from cis- and trans-tetrazonium gold(III) salts for electrochemical and photothermal mirror properties

   https://doi.org/10.1016/j.jorganchem.2021.121681  

   Panicker, Seema ; Marcano, Aristides ; Isah, Shehu ; Kenney, Brianna ; Workie, Bizuneh ; Han, Changseok ; Lee, Haesung ; Chehimi, Mohamed M. ; Mohamed, Ahmed A. ( March 2021 , Journal of Organometallic Chemistry)

   null (Ed.)
5. Gold Nanoclusters: Bridging Gold Complexes and Plasmonic Nanoparticles in Photophysical Properties

   https://doi.org/10.3390/nano9070933  

   Zhou, Meng ; Zeng, Chenjie ; Li, Qi ; Higaki, Tatsuya ; Jin, Rongchao ( July 2019 , Nanomaterials)

   Recent advances in the determination of crystal structures and studies of optical properties of gold nanoclusters in the size range from tens to hundreds of gold atoms have started to reveal the grand evolution from gold complexes to nanoclusters and further to plasmonic nanoparticles. However, a detailed comparison of their photophysical properties is still lacking. Here, we compared the excited state behaviors of gold complexes, nanolcusters, and plasmonic nanoparticles, as well as small organic molecules by choosing four typical examples including the Au10 complex, Au25 nanocluster (1 nm metal core), 13 diameter Au nanoparticles, and Rhodamine B. To compare their photophysical behaviors, we performed steady-state absorption, photoluminescence, and femtosecond transient absorption spectroscopic measurements. It was found that gold nanoclusters behave somewhat like small molecules, showing both rapid internal conversion (<1 ps) and long-lived excited state lifetime (about 100 ns). Unlike the nanocluster form in which metal–metal transitions dominate, gold complexes showed significant charge transfer between metal atoms and surface ligands. Plasmonic gold nanoparticles, on the other hand, had electrons being heated and cooled (~100 ps time scale) after photo-excitation, and the relaxation was dominated by electron–electron scattering, electron–phonon coupling, and energy dissipation. In both nanoclusters and plasmonic nanoparticles, one can observe coherent oscillations of the metal core, but with different fundamental origins. Overall, this work provides some benchmarking features for organic dye molecules, organometallic complexes, metal nanoclusters, and plasmonic nanoparticles. 

   more » « less