Article
Chemistry, Multidisciplinary
Kevin M. Roccapriore, Maxim Ziatdinov, Shin Hum Cho, Jordan A. Hachtel, Sergei Kalinin
Summary: The correlation between local nanoparticle geometries and their plasmonic responses is established using encoder-decoder neural networks in this study. The simplified descriptions allow high-accuracy predictions of local responses based on geometries, paving the way for stochastic design of nanoplasmonic structures. This approach creates a path towards determining configurations that yield the spectrum closest to the desired one.
Article
Chemistry, Physical
Alice Apponi, Domenica Convertino, Neeraj Mishra, Camilla Coletti, Mauro Iodice, Franco Frasconi, Federico Pilo, Narcis Silviu Blaj, Daniele Paoloni, Ilaria Rago, Giovanni De Bellis, Gianluca Cavoto, Alessandro Ruocco
Summary: In this study, accurate transmission measurements of electrons below 1 keV through suspended monolayer graphene were reported. The monolayer graphene was grown using chemical vapor deposition and transferred onto transmission electron microscopy (TEM) grids. The transparency of graphene was obtained by measuring the direct beam current and transmitted current. The experimental results showed a transmission rate ranging from about 20% to about 80% for monolayer graphene within the experimental electron energy range. The high quality and grid coverage of the suspended graphene were confirmed through various characterization techniques. Additionally, evidence of suspended monolayer graphene was observed after annealing the samples in vacuum at 550 degrees C.
Article
Chemistry, Multidisciplinary
Amelia C. Y. Liu, Timothy J. Davis, Toon Coenen, Sangeetha Hari, Lenard M. Voortman, Zhou Xu, Gangcheng Yuan, Patrycja M. Ballard, Alison M. Funston, Joanne Etheridge
Summary: Waveguide modes in chemically-grown silver nanowires on silicon nitride substrates are observed using cathodoluminescence excited by high-energy electrons. The presence of a long-range, travelling surface plasmon mode modulates the coupling efficiency of incident electron energy into the nanowires, causing oscillations in the measured cathodoluminescence. The experimental data are modeled using the theory of surface plasmon polariton modes, allowing for extraction of complex mode wavenumbers and excitation strength of the long-range surface plasmon mode.
Article
Chemistry, Multidisciplinary
Kenan Elibol, Peter A. Van Aken
Summary: Controlled fabrication of devices for plasmonics on suspended graphene enables tunable localized surface plasmon resonances and the creation of hybrid 3D-2D systems, which have potential applications in adjustable dipole-dipole coupling and plasmon-mediated catalysis.
Article
Nanoscience & Nanotechnology
Xinxin Zhou, Cong Guo, Zhongping Wang, Mingming Fu, Sheng Wei, Xiaoqing Liu, Sanqin Wu, Li Wang
Summary: The role of silver localized surface plasmons on the luminescence of a Si(111)-(7 x 7) surface was investigated using scanning tunneling microscopy at 77 K. It was found that the luminescence intensity from the Si surface underneath the Ag islands was significantly enhanced by about one order due to the strong coupling between the surface states of the Si and the LSPs of the Ag islands. In addition, light emission originating from the irradiation decay of the Ag plasmons was also detected during the study.
Article
Chemistry, Multidisciplinary
Kenan Elibol, Peter A. van Aken
Summary: We report the adjustment of charge-transfer-plasmon (CTP) resonances in aluminum bowties on graphene through controlled nanofabrication and focused electron-beam irradiation. The CTP resonances show different frequency shifts and decay behaviors with changes in the junction width and electron-beam irradiation, revealing the tunability and sensitivity of the resonances.
Article
Nanoscience & Nanotechnology
Michal Horak, Andrea Konecna, Tomas Sikola, Vlastimil Krapek
Summary: Electron energy loss spectroscopy (EELS) is commonly used to study localized surface plasmon modes of plasmonic antennas, but it has limited spectral resolution and difficulty in resolving closely spaced modes. In this study, we address this issue by analyzing the plasmon modes of a dimer plasmonic antenna composed of two gold discs. We propose metrics based on spectral and spatial sensitivity to resolve the modes and validate them through electrodynamic simulations. Experimental data demonstrate the capability of these metrics to resolve and identify the modes, except for the transverse bonding and antibonding modes. Overall, the spatio-spectral metrics enhance the information extracted from EELS for plasmonic antennas.
Article
Chemistry, Multidisciplinary
Vana Chinnappa Chinnabathini, Fons Dingenen, Rituraj Borah, Imran Abbas, Johan van der Tol, Zviadi Zarkua, Francesco D'Acapito, Thi Hong Trang Nguyen, Peter Lievens, Didier Grandjean, Sammy W. Verbruggen, Ewald Janssens
Summary: Cluster beam deposition is used to fabricate well-defined bimetallic plasmonic photocatalysts, enhancing their activity and providing insights into their properties. The deposited clusters exhibit composition-dependent electron transfer and composition-dependent enhancement of their photocatalytic activity under simulated solar light. The study confirms that Au0.3Ag0.7 composition shows the largest near-field enhancement and superior photocatalytic self-cleaning activity, attributed to the plasmonic effect of the bimetallic clusters.
Article
Chemistry, Multidisciplinary
Kevin M. Roccapriore, Shin-Hum Cho, Andrew R. Lupini, Delia J. Milliron, Sergei Kalinin
Summary: The spatial confinement of matter in functional nanostructures has positioned them at the forefront of nanoscience, serving as playgrounds for exotic physics and quantum phenomena as well as finding applications in various fields. Through modern synthesis processes and precise sculpting, the plasmonic response of nanoparticles can be effectively modified, offering a wide range of possibilities for nanophotonic design.
Article
Chemistry, Multidisciplinary
Kunyen Liao, Kiyou Shibata, Teruyasu Mizoguchi
Summary: Grain boundaries significantly affect the coefficient of thermal expansion in polycrystals. This study used EELS to directly measure CTE in different types of grain boundaries, revealing variations in thermodynamic properties and demonstrating the potential of EELS for probing local thermal properties at nanometer-scale resolution.
Article
Chemistry, Physical
Thomas Blum, Jeffery Graves, Michael J. Zachman, Felipe Polo-Garzon, Zili Wu, Ramakrishnan Kannan, Xiaoqing Pan, Miaofang Chi
Summary: Forming an ultra-thin, permeable encapsulation oxide-support layer on a metal catalyst surface is considered an effective strategy for achieving a balance between high stability and high activity in heterogenous catalysts, but identifying such a trace layer has been challenging. A new robust, unsupervised machine learning data analysis method has been developed to accurately reveal trace encapsulation layers in STEM-EELS datasets that are otherwise overlooked, providing a reliable tool for analyzing catalyst encapsulation.
Article
Physics, Applied
A. Firoozi, R. Khordad, H. R. Rastegar Sedehi
Summary: Due to the increasing importance of nanosensors in the early diagnosis of diseases, researchers propose a structure consisting of plasmonic nanoshells with spherical and ellipsoidal geometry to calculate the refractive index changes. The sensitivity of the nanosensor is computed and factors such as geometry, material, dimensions, thickness, and surrounding environment are studied. The results show that ellipsoidal nanoshells are more sensitive to RI changes, and bimetallic nanoshells can exponentially increase the sensitivity of the nanosensor.
MODERN PHYSICS LETTERS B
(2023)
Article
Chemistry, Multidisciplinary
Wan Zakiah Wan Ismail, Judith M. Dawes
Summary: Rough silver-gold bimetallic nanoparticles were developed for random lasing. By depositing gold atoms on the surface of silver nanoparticles, bimetallic nanoparticles with nanogaps and extinction effect were obtained. When these nanoparticles were added to a dye solution, they generated random lasing with spectral narrowing and reduced lasing threshold compared to silver nanoparticles. This can be attributed to the localized surface plasmon effects and the rough surface of the nanoparticles.
Article
Materials Science, Multidisciplinary
Sang-Yeob Lim, SungSoo Kim, Jucheol Park, Gyeong-Geun Lee, Kunok Chang
Summary: This study used STEM-EEL S to investigate hydride phases inside Zr-2.5Nb pressure tubes, revealing two different possibilities of phase characteristics, which are important for evaluating the mechanical integrity of the pressure tubes.
JOURNAL OF NUCLEAR MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Kevin M. Roccapriore, Sergei Kalinin, Maxim Ziatdinov
Summary: Physics-driven discovery in an autonomous experiment using machine learning is a dream application. The research presented here develops a deep kernel learning workflow that combines correlative prediction, physics-based acquisition function selection, and flexible scalarization function to enable physical discovery in automated experiments. This approach can capture complex spatial features in realistic materials images and dynamically learn structure-property relationships.
Article
Chemistry, Multidisciplinary
Yu-Chuan Lin, Chenze Liu, Yiling Yu, Eva Zarkadoula, Mina Yoon, Alexander A. Puretzky, Liangbo Liang, Xiangru Kong, Yiyi Gu, Alex Strasser, Harry M. Meyer, Matthias Lorenz, Matthew F. Chisholm, Ilia N. Ivanov, Christopher M. Rouleau, Gerd Duscher, Kai Xiao, David B. Geohegan
Article
Chemistry, Multidisciplinary
Yiyi Gu, Hui Cai, Jichen Dong, Yiling Yu, Anna N. Hoffman, Chenze Liu, Akinola D. Oyedele, Yu-Chuan Lin, Zhuozhi Ge, Alexander A. Puretzky, Gerd Duscher, Matthew F. Chisholm, Philip D. Rack, Christopher M. Rouleau, Zheng Gai, Xiangmin Meng, Feng Ding, David B. Geohegan, Kai Xiao
ADVANCED MATERIALS
(2020)
Article
Nanoscience & Nanotechnology
Krishna P. Koirala, Venkatanarayana P. Sandireddy, Hernando Garcia, Gerd Duscher, Ramki Kalyanaraman
Article
Physics, Applied
Krishna Prasad Koirala, Aniruddha Deb, Sara Bey, Tatiana Allen, Ritesh Sachan, Venkatanarayana Prasad Sandireddy, Chenze Liu, Gerd Duscher, James Penner-Hahn, Ramki Kalyanaraman
Summary: Recent studies have found that amorphous oxide thin films made from Fe and lanthanides exhibit rich properties including magnetic, optical, and electronic features, as well as room-temperature magneto-electric coupling with multiferroics. These films show high disorder and slight oxidation after annealing, with high electrical conductivity, Hall mobility, and complex magnetic and optical properties at room temperature.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Ting Zheng, Yu-Chuan Lin, Yiling Yu, Pavel Valencia-Acuna, Alexander A. Puretzky, Riccardo Torsi, Chenze Liu, Ilia N. Ivanov, Gerd Duscher, David B. Geohegan, Zhenhua Ni, Kai Xiao, Hui Zhao
Summary: This study reports the excitonic dynamics of Janus transition metal dichalcogenide monolayers, showing that excitons in Janus structures form faster and have significantly longer radiative recombination lifetime compared to pristine samples. These results provide fundamental insight into the optical properties of Janus transition metal dichalcogenides.
Article
Chemistry, Physical
Krishna Prasad Koirala, Jingxuan Ge, Ramki Kalyanaraman, Gerd Duscher
Summary: This study presents the first evidence of localized interface plasmons in CoAg bimetallic nanoparticles using scanning transmission electron microscopy-electron energy-loss spectroscopy. The oscillation frequency of localized interface plasmons falls between in-plane dipole localized surface plasmon resonance (LSPR) mode and quasiplanar mode, showing stronger resonance compared to in-plane dipole LSPR. The direct detection of plasmons confined to the interface region could drive future engineering for improved plasmonic activity in bimetallic interfaces.
Article
Chemistry, Multidisciplinary
Yiling Yu, Gang Seob Jung, Chenze Liu, Yu-Chuan Lin, Christopher M. Rouleau, Mina Yoon, Gyula Eres, Gerd Duscher, Kai Xiao, Stephan Irle, Alexander A. Puretzky, David B. Geohegan
Summary: The study investigates the synthesis of twisted 2D bilayers through chemical vapor deposition, revealing the preservation of misorientation angles in twisted bilayers and a threshold for their appearance. Simulations and experimental results explain the strain and growth processes during crystal coalescence, shedding light on the formation of grain boundaries and faceting along the GB.
Article
Chemistry, Multidisciplinary
Chenze Liu, Yu-Chuan Lin, Mina Yoon, Yiling Yu, Alexander A. Puretzky, Christopher M. Rouleau, Matthew F. Chisholm, Kai Xiao, Gyula Eres, Gerd Duscher, David B. Geohegan
Summary: This study used in situ laser-heating within a transmission electron microscope to investigate the crystallization and coalescence stages of amorphous precursors deposited by pulsed laser deposition guided by 2D crystalline substrates into van der Waals epitaxial heterostructures.
Article
Materials Science, Multidisciplinary
M. F. Chisholm, D. Shin, G. Duscher, M. P. Oxley, L. F. Allard, J. D. Poplawsky, A. Shyam
Summary: This study accurately determines the atomic structure of semi-coherent precipitate interfaces using aberration-corrected scanning transmission electron microscopy and first-principles calculations, revealing critical features that determine the thermal stability of precipitation-hardened alloys.Unexpected misfit dislocations are found to be key in accommodating the misfit between the matrix and strengthening phase.
Article
Nanoscience & Nanotechnology
Krishna Prasad Koirala, Hernando Garcia, Venkatanarayana Prasad Sandireddy, Ramki Kalyanaraman, Gerd Duscher
Summary: The discovery of giant negative nonlinear refraction and nonlinear Faraday rotation at 1550 nm using Fe-Ag bimetallic nanopyramids was reported, showing a very large third-order nonlinear refractive index and magneto-optical susceptibility. This nanoscale system opens up possibilities for future miniaturization of multifunctional devices at telecommunication wavelengths.
ACS APPLIED NANO MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Kai Wang, Lizhi Zhang, Giang D. Nguyen, Xiahan Sang, Chenze Liu, Yiling Yu, Wonhee Ko, Raymond R. Unocic, Alexander A. Puretzky, Christopher M. Rouleau, David B. Geohegan, Lei Fu, Gerd Duscher, An-Ping Li, Mina Yoon, Kai Xiao
Summary: Defects are common in 2D materials and can greatly influence their properties. The authors have developed a method using Au-assisted chemical vapor deposition to selectively form antisite defects in WS2 monolayers. Experimental and theoretical analyses confirm the effectiveness of this bottom-up synthesis approach, with potential applications in the synthesis of other 2D materials.
ADVANCED MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Yiyi Gu, Lizhi Zhang, Hui Cai, Liangbo Liang, Chenze Liu, Anna Hoffman, Yiling Yu, Austin Houston, Alexander A. Puretzky, Gerd Duscher, Philip D. Rack, Christopher M. Rouleau, Xiangmin Meng, Mina Yoon, David B. Geohegan, Kai Xiao
Summary: This study reports an ambient-pressure chemical vapor deposition approach to synthesize metastable monoclinic PdSe2. Monoclinic PdSe2 is selectively synthesized under S-deficient conditions, and its structure and properties are characterized by first-principles calculations and experimental techniques. Monoclinic PdSe2 exhibits strong optical anisotropy and high electron mobility, which is of significant importance for the synthesis of other 2D transition metal dichalcogenides.
Article
Physics, Applied
Venkatanarayana Prasad Sandireddy, Krishna Prasad Koirala, Gerd Duscher, Ramki Kalyanaraman
Summary: The rapid laser heating of Ag nanopyramids and thin films in different fluids demonstrates varying behaviors of material vaporization, ranging from explosive vaporization in vacuum to increased localization of vaporized material under bulk fluids. The size and density of nanoparticles on surfaces can be controlled by the vaporization behavior of metal under bounding fluids, offering insights into the highly non-equilibrium process of explosive vaporization. Additionally, the redeposited material particles show significant changes in size and density under different fluid environments, indicating the potential for tailored nanoparticle synthesis.
JOURNAL OF APPLIED PHYSICS
(2021)
