Enhancement of X-ray emission from nanocolloidal gold suspensions under double-pulse excitation

• Wei-Hung Hsu,
• Frances Camille P. Masim,
• Armandas Balčytis,
• Hsin-Hui Huang,
• Tetsu Yonezawa,
• Aleksandr A. Kuchmizhak,
• Saulius Juodkazis and
• Koji Hatanaka

Beilstein J. Nanotechnol. 2018, 9, 2609–2617, doi:10.3762/bjnano.9.242

• solutions maximizes the volume of εr-near-zero (ENZ) regions and overlaps with the focal volume of the main pulse. Those ENZ regions are responsible for the most efficient energy deposition via absorption and define the transition of the propagating light to the ENZ surface (an optical near-field). This

Au–Si plasmonic platforms: synthesis, structure and FDTD simulations

• Anna Gapska,
• Marcin Łapiński,
• Paweł Syty,
• Wojciech Sadowski,
• Józef E. Sienkiewicz and
• Barbara Kościelska

Beilstein J. Nanotechnol. 2018, 9, 2599–2608, doi:10.3762/bjnano.9.241

• distribution on the nanoparticle plates. One of the ways to go beyond this classical model is to add to the Maxwell’s FDTD method the quantum-mechanical description of the near-field distribution by using the time-dependent Schrödinger equations [10]. However, here one of the difficulties lies in the

Directional light beams by design from electrically driven elliptical slit antennas

• Shuiyan Cao,
• Eric Le Moal,
• Quanbo Jiang,
• Aurélien Drezet,
• Serge Huant,
• Jean-Paul Hugonin,
• Gérald Dujardin and
• Elizabeth Boer-Duchemin

Beilstein J. Nanotechnol. 2018, 9, 2361–2371, doi:10.3762/bjnano.9.221

• , bull’s-eye, nanoparticle dimer, or wire antennas), coupled in the near field (or incorporating in their design) an electrically driven nanosource of surface plasmon polaritons (SPPs, light waves coupled to electron density oscillations at a metal–dielectric interface). In particular, the electrical SPP

Metal–dielectric hybrid nanoantennas for efficient frequency conversion at the anapole mode

• Valerio F. Gili,
• Lavinia Ghirardini,
• Davide Rocco,
• Giuseppe Marino,
• Ivan Favero,
• Iännis Roland,
• Giovanni Pellegrini,
• Lamberto Duò,
• Marco Finazzi,
• Luca Carletti,
• Andrea Locatelli,
• Aristide Lemaître,
• Dragomir Neshev,
• Costantino De Angelis,
• Giuseppe Leo and
• Michele Celebrano

Beilstein J. Nanotechnol. 2018, 9, 2306–2314, doi:10.3762/bjnano.9.215

• spectrum. In this frame, AlGaAs nanoantennas demonstrated to be extremely efficient sources of second harmonic radiation. In particular, the nonlinear polarization of an optical system pumped at the anapole mode can be potentially boosted, due to both the strong dip in the scattering spectrum and the near

• -field enhancement, which are characteristic of this mode. Plasmonic nanostructures, on the other hand, remain the most promising solution to achieve strong local field confinement, especially in the NIR, where metals such as gold display relatively low losses. Results: We present a nonlinear hybrid

Dumbbell gold nanoparticle dimer antennas with advanced optical properties

• Janning F. Herrmann and
• Christiane Höppener

Beilstein J. Nanotechnol. 2018, 9, 2188–2197, doi:10.3762/bjnano.9.205

• asymmetric gold nanoparticle antennas (AuNPs) with improved optical near-field properties based on the formation of sub-nanometer size gaps, which are suitable for studying matter with high-resolution and single molecule sensitivity. These dumbbell antennas are characterized in regard to their far-field and

• near-field properties and are compared to similar dimer and trimer antennas with larger gap sizes. The tailoring of the gap size down to sub-nanometer length scales is based on the integration of rigid macrocyclic cucurbituril molecules. Stable dimer antennas are formed with an improved ratio of the

• electromagnetic field enhancement and confinement. This ratio, taken as a measure of the performance of an antenna, can even exceed that exhibited by trimer AuNP antennas composed of comparable building blocks with larger gap sizes. Fluctuations in the far-field and near-field properties are observed, which are

Self-assembled quasi-hexagonal arrays of gold nanoparticles with small gaps for surface-enhanced Raman spectroscopy

• Emre Gürdal,
• Simon Dickreuter,
• Fatima Noureddine,
• Pascal Bieschke,
• Dieter P. Kern and
• Monika Fleischer

Beilstein J. Nanotechnol. 2018, 9, 1977–1985, doi:10.3762/bjnano.9.188

• near-field-enhanced bio-analytics of molecules. SERS was demonstrated by measuring Raman spectra of 4-MBA on the gold nanoparticles. It was verified that a smaller inter-particle distance leads to an increased SERS signal. Keywords: block copolymer; electroless deposition; gold nanoparticles; micelle

• spectral range and exhibit a very strong near-field in their close vicinity [1]. The plasmonic resonances of gold nanoparticles can be varied by changes in size, shape and geometrical arrangement [2][3]. A high density of intense hotspots can be induced by narrow gap sizes and rough surfaces [4][5]. These

• increased near-field [29]. To estimate a lower boundary for the enhancement factor of the particles we compared the corrected Raman spectra of sample A to a measurement of 4-MBA on a smooth gold film with a thickness of 70 nm, also on a silicon substrate. Both samples were treated in exactly the same way

Electromigrated electrical optical antennas for transducing electrons and photons at the nanoscale

• Arindam Dasgupta,
• Mickaël Buret,
• Nicolas Cazier,
• Marie-Maxime Mennemanteuil,
• Reinaldo Chacon,
• Kamal Hammani,
• Jean-Claude Weeber,
• Juan Arocas,
• Laurent Markey,
• Gérard Colas des Francs,
• Alexander Uskov,
• Igor Smetanin and
• Alexandre Bouhelier

Beilstein J. Nanotechnol. 2018, 9, 1964–1976, doi:10.3762/bjnano.9.187

• antennas are devices operating at frequencies from visible light to infrared [8]. They were primarily developed to enhance light–matter near-field interactions [9] via the excitation of surface plasmons for metal-based devices [10] or Mie resonances for dielectric antennas [11][12]. Interestingly, optical

Optical near-field mapping of plasmonic nanostructures prepared by nanosphere lithography

• Gitanjali Kolhatkar,
• Alexandre Merlen,
• Jiawei Zhang,
• Chahinez Dab,
• Gregory Q. Wallace,
• François Lagugné-Labarthet and
• Andreas Ruediger

Beilstein J. Nanotechnol. 2018, 9, 1536–1543, doi:10.3762/bjnano.9.144

• Department and Centre for Materials and Biomaterials, 1151 Richmond Street, London, ON, N6A5B7, Canada 10.3762/bjnano.9.144 Abstract We introduce a simple, fast, efficient and non-destructive method to study the optical near-field properties of plasmonic nanotriangles prepared by nanosphere lithography

• . Using a rectangular Fourier filter on the blurred signal together with filtering of the lower spatial frequencies to remove the far-field contribution, the pure near-field contributions of the optical images were extracted. We performed measurements using two excitation wavelengths (532.1 nm and 632.8

• results to numerical simulations, where agreement is obtained, thereby confirming the near-field nature of the images. Our approach does not require any advanced equipment and we suggest that it could be applied to any type of sample, while keeping the measurement times reasonably short. Keywords

Cathodoluminescence as a probe of the optical properties of resonant apertures in a metallic film

• Kalpana Singh,
• Evgeniy Panchenko,
• Babak Nasr,
• Amelia Liu,
• Lukas Wesemann,
• Timothy J. Davis and
• Ann Roberts

Beilstein J. Nanotechnol. 2018, 9, 1491–1500, doi:10.3762/bjnano.9.140

• coupling between unit cells [7]. Near field optical microscopy is another method that has been used to probe optical resonances of various nanostructures. Although the technique provides better-than-diffraction-limited resolution, image interpretation is complex due to the interaction between the tip and

Excitation of nonradiating magnetic anapole states with azimuthally polarized vector beams

• Aristeidis G. Lamprianidis and
• Andrey E. Miroshnichenko

Beilstein J. Nanotechnol. 2018, 9, 1478–1490, doi:10.3762/bjnano.9.139

• the electric dipole radiation vanishes completely. It was demonstrated that such states can be explained by the co-existence of electric and toroidal dipole moments, simultaneously excited inside dielectric nanoparticles. Despite their different near-field configurations both dipole moments emit with

• comparable toroidal and electric dipoles might result in nonradiating anapole excitation [10][11][12][13][14]. It has a number of interesting features and can be used to design near-field laser [15], to obtain high-efficiency harmonic generation [16], to achieve pure magnetic dipole scattering without

• useful applications in biosensing, i.e., in the detection of molecules that interact strongly once exposed to magnetic field hotspots, which nanoparticles in a magnetic anapole state can offer in their near field. Moreover, the signal-to-noise ratio of an MRI machine, that is defined as the ratio of the

Surface characterization of nanoparticles using near-field light scattering

• Eunsoo Yoo,
• Yizhong Liu,
• Chukwuazam A. Nwasike,
• Sebastian R. Freeman,
• Brian C. DiPaolo,
• Bernardo Cordovez and
• Amber L. Doiron

Beilstein J. Nanotechnol. 2018, 9, 1228–1238, doi:10.3762/bjnano.9.114

• using near-field light scattering. The local scattering intensity is correlated with the distance between the particle and waveguide, which is affected by the size of the particle (coating thickness) as well as the interactions between the particle and waveguide (related to the zeta potential of the

• coating). Therefore, we report here the use of near-field light scattering using nanophotonic force microscopy (using a NanoTweezerTM instrument, Halo Labs) to determine the changes that occurred in hydrated particle characteristics, which is accompanied by an analytical model. Furthermore, we found that

• reaction kinetics at the particle surface. Keywords: nanoparticle surface properties; nanoparticles; nanophotonic force microscopy; near-field light scattering; superparamagnetic iron oxide; Introduction Nanotechnology is an increasingly integral part of modern medicine, predominantly in the fields of

Valley-selective directional emission from a transition-metal dichalcogenide monolayer mediated by a plasmonic nanoantenna

• Haitao Chen,
• Mingkai Liu,
• Lei Xu and
• Dragomir N. Neshev

Beilstein J. Nanotechnol. 2018, 9, 780–788, doi:10.3762/bjnano.9.71

• plasmonic modes are excited [29][30][31]. In particular, localized emitters could effectively excite the higher-order modes of the nanoantenna, which are usually only weakly coupled to free-space plane waves [32][33] but can dramatically modify the radiation of the emitters. Importantly, the near-field and

• emission from the two valleys of the TMDCs via near-field coupling to a plasmonic nanoantenna is schematically shown in Figure 1a. When the coupled TMDC–nanoantenna system is excited by light of different circular polarizations, the emission from the two valleys (K and K′) will be emitted into opposite

• averaging over all the nine positions. Supporting Information Supporting Information File 20: Additional experimental data. Supporting Information features vectorial near-field profiles for the dipole-nanoantenna system, and the radiation pattern of chiral emitters without nanoantenna. Acknowledgements We

High-contrast and reversible scattering switching via hybrid metal-dielectric metasurfaces

• Jonathan Ward,
• Khosro Zangeneh Kamali,
• Lei Xu,
• Guoquan Zhang,
• Andrey E. Miroshnichenko and
• Mohsen Rahmani

Beilstein J. Nanotechnol. 2018, 9, 460–467, doi:10.3762/bjnano.9.44

• ][12][13], which utilize the interaction between light and metallic nanoparticles to generate surface plasmon resonances, inducing a strong electromagnetic field on the metallic surface. They benefit from a large tunability and capability to significantly enhance the near-field intensity, and have

• system. Both plasmonic and dielectric modes exhibit intense near-field distributions [8][9][46]. It is well-known that the near-field associated with plasmonic and dielectric resonances of the individual particles extends some distance away from it [47][48]. These characteristics make the modes very

• the related electric near-field distributions in the silicon disk for a plane wave with λFW = 1235 nm at I0 = 1 GW/cm2. As can be seen from Figure 6a, the efficiency of third harmonic generation can be enhanced by one order of magnitude due to the emergence of the Fano-like resonance during the

Periodic structures on liquid-phase smectic A, nematic and isotropic free surfaces

• Anna N. Bagdinova,
• Evgeny I. Demikhov,
• Nataliya G. Borisenko,
• Sergei M. Tolokonnikov,
• Gennadii V. Mishakov and
• Andrei V. Sharkov

Beilstein J. Nanotechnol. 2018, 9, 342–352, doi:10.3762/bjnano.9.34

• atomic force microscope (AFM) and a scanning near-field optical microscope (SNOM). Images of the SmA phase free surface obtained by the polarized microscope and ISSA are in good correlation and show a well-known focal domain structure. The new periodic stripe structure was observed by scanning near-field

• , such as interferometric surface structure analyzers (ISSAs, i.e., nanoprofilometer), atomic force microscope (AFM) [5][6][7][8] and a scanning near-field optical microscope (SNOM) [9][10] has been made. To study the liquid crystalline free boundary structures, common nanotechnology tools are used, for

• near-field optical microscope (SNOM). The SNOM has a sharpened optical fiber probe with an aperture much smaller than the wavelength. The probe detects (or excites) the so-called "evanescent" ("vanishing") component of the alternating electric field of the optical signal, which rapidly decays at short

Comparative study of post-growth annealing of Cu(hfac)₂, Co₂(CO)₈ and Me₂Au(acac) metal precursors deposited by FEBID

• Marcos V. Puydinger dos Santos,
• Aleksandra Szkudlarek,
• Artur Rydosz,
• Carlos Guerra-Nuñez,
• Fanny Béron,
• Kleber R. Pirota,
• Stanislav Moshkalev,
• José Alexandre Diniz and
• Ivo Utke

Beilstein J. Nanotechnol. 2018, 9, 91–101, doi:10.3762/bjnano.9.11

• applications, such as gas [14][15], strain [16], magnetic [12][17] and thermal sensors [18], besides nano-antennas as probes for scanning near-field optical microscopy (SNOM) [19]. Other applications comprising superconducting [20] and plasmonic [21] structures, nanoalloys for nanoelectronic applications [22

Hyperthermic intracavitary nanoaerosol therapy (HINAT) as an improved approach for pressurised intraperitoneal aerosol chemotherapy (PIPAC): Technical description, experimental validation and first proof of concept

• Daniel Göhler,
• Stephan Große,
• Alexander Bellendorf,
• Thomas Albert Falkenstein,
• Mehdi Ouaissi,
• Jürgen Zieren,
• Michael Stintz and
• Urs Giger-Pabst

Beilstein J. Nanotechnol. 2017, 8, 2729–2740, doi:10.3762/bjnano.8.272

• electrode and grounded peritoneum. Due to the asymmetric conditions of the capnoperitoneum, peritoneal regions located in the near field of the electrode experience a more intensified droplet deposition than regions in the far field. Excess aerosol In contrast to PIPAC-MIP, the HINAT-LAU aerosol is

Laser-assisted fabrication of gold nanoparticle-composed structures embedded in borosilicate glass

• Nikolay Nedyalkov,
• Mihaela Koleva,
• Nadya Stankova,
• Rosen Nikov,
• Mitsuhiro Terakawa,
• Yasutaka Nakajima,
• Lyubomir Aleksandrov and
• Reni Iordanova

Beilstein J. Nanotechnol. 2017, 8, 2454–2463, doi:10.3762/bjnano.8.244

• ], whose impact on the optical properties of the nanoparticle systems is not fully described. This effect is also responsible for the specific distribution of the electromagnetic field in the near-field zone, characterized by “hot spot” areas with a strongly enhanced intensity [2]. The practical

Angstrom-scale flatness using selective nanoscale etching

• Takashi Yatsui,
• Hiroshi Saito and
• Katsuyuki Nobusada

Beilstein J. Nanotechnol. 2017, 8, 2181–2185, doi:10.3762/bjnano.8.217

• realization of flat surfaces on the angstrom scale is required in advanced devices to avoid loss due to carrier (electron and/or photon) scattering. In this work, we have developed a new surface flattening method that involves near-field etching, where optical near-fields (ONFs) act to dissociate the

• molecules. ONFs selectively generated at the apex of protrusions on the surface selectively etch the protrusions. To confirm the selective etching of the nanoscale structure, we compared near-field etching using both gas molecules and ions in liquid phase. Using two-dimensional Fourier analysis, we found

• that near-field etching is an effective way to etch on the scale of less than 10 nm for both wet and dry etching techniques. In addition, near-field dry etching may be effective for the selective etching of nanoscale structures with large mean free path values. Keywords: Angstrom-scale flatness

Ta₂N₃ nanocrystals grown in Al₂O₃ thin layers

• Krešimir Salamon,
• Maja Buljan,
• Iva Šarić,
• Mladen Petravić and
• Sigrid Bernstorff

Beilstein J. Nanotechnol. 2017, 8, 2162–2170, doi:10.3762/bjnano.8.215

• light to nano-scale structures via local surface plasmon resonance (LSPR) [1]. LSPR produces a strong near-field enhancement and a local heating [2][3], which are considered to be promising in several applications ranging from surface-enhanced Raman scattering [4], to catalysis [5] and heat-assisted

Magnetic properties of optimized cobalt nanospheres grown by focused electron beam induced deposition (FEBID) on cantilever tips

• Soraya Sangiao,
• César Magén,
• Darius Mofakhami,
• Grégoire de Loubens and
• José María De Teresa

Beilstein J. Nanotechnol. 2017, 8, 2106–2115, doi:10.3762/bjnano.8.210

• investigation of spin dynamics at the nanoscale [41]. This near field scanning probe technique allows magnetic resonance imaging (MRI) with nanometer spatial resolution and extreme spin sensitivity [42] and the investigation of spin waves at the sub-micrometer scale [43][44][45]. In these applications, very

Synthesis and characterization of noble metal–titania core–shell nanostructures with tunable shell thickness

• Bartosz Bartosewicz,
• Marta Michalska-Domańska,
• Malwina Liszewska,
• Dariusz Zasada and
• Bartłomiej J. Jankiewicz

Beilstein J. Nanotechnol. 2017, 8, 2083–2093, doi:10.3762/bjnano.8.208

• interesting materials for application in dye-sensitized solar cells (DSSCs) and photocatalysis. In fact, it has been shown that plasmonic nanostructures can enhance the efficiency of DSSCs by four possible mechanisms [66]. The far-field coupling of scattered light and the near-field coupling of

Near-infrared-responsive, superparamagnetic Au@Co nanochains

• Varadee Vittur,
• Arati G. Kolhatkar,
• Shreya Shah,
• Irene Rusakova,
• Dmitri Litvinov and
• T. Randall Lee

Beilstein J. Nanotechnol. 2017, 8, 1680–1687, doi:10.3762/bjnano.8.168

• shift from that of a single particle because of near-field coupling. This shift in wavelength is proportional to the number of nanoparticles in the chain [31][32]. These new types of magnetic nanostructures find use in several applications, such as combined MRI imaging and photothermal treatment and bio

Near-field surface plasmon field enhancement induced by rippled surfaces

• Mario D’Acunto,
• Francesco Fuso,
• Ruggero Micheletto,
• Makoto Naruse,
• Francesco Tantussi and
• Maria Allegrini

Beilstein J. Nanotechnol. 2017, 8, 956–967, doi:10.3762/bjnano.8.97

• scanning near-field optical microscopy. Keywords: aperture scanning near-field optical microscopy; gold rippled surface; localized hot spots; metal–dielectric−metal nanogaps; surface plasmon resonance; Introduction Metal nanostructures capable of producing localized surface plasmon polaritons (SPPs) are

• of fundamental relevance to study near-field nonlinear optical phenomena [1][2]. Particularly relevant is the strong electric field enhancement on resonance that can be of special interest for various applications, such as surface-enhanced Raman spectroscopy (SERS) [3][4], tip-enhanced Raman

• spectroscopy (TERS) [5], plasmonic photovoltaics [6][7][8], plasmonic nanosensors [9][10], and near-field optical theory [2][11][12]. It is commonly accepted that enormous field enhancements at the resonance of the optical response applied to randomly patterned metal nanostructures are highly dependent upon

Relationships between chemical structure, mechanical properties and materials processing in nanopatterned organosilicate fins

• Gheorghe Stan,
• Richard S. Gates,
• Qichi Hu,
• Kevin Kjoller,
• Craig Prater,
• Kanwal Jit Singh,
• Ebony Mays and
• Sean W. King

Beilstein J. Nanotechnol. 2017, 8, 863–871, doi:10.3762/bjnano.8.88

• scanning probe microscopy (SPM) [15][16][17][18][19][20][21]). It is due to the non-existence of techniques to identify chemical structures with nanometer lateral (in-plane) resolution. Scatterometry and near-field optical microscopy (NSOM) techniques have allowed sub-wavelength features to be resolved [22

• atomic force microscopy (AFM) and exploiting either near-field optical enhancements produced by the probe tip [25][26], or using the AFM probe to detect various photoinduced thermo-mechanical responses [24][27]. However, these techniques have yet to be routinely combined with other nanoscale SPM

Surface improvement of organic photoresists using a near-field-dependent etching method

• Felix J. Brandenburg,
• Tomohiro Okamoto,
• Hiroshi Saito,
• Benjamin Leuschel,
• Olivier Soppera and
• Takashi Yatsui

Beilstein J. Nanotechnol. 2017, 8, 784–788, doi:10.3762/bjnano.8.81

• have developed a near-field etching technique that provides selective etching of surface protrusions, resulting in an atomically flat surface. To achieve finer control, we examine the importance of the wavelength of the near-field etching laser. Using light sources at wavelengths of 325 and 405 nm

• reduction of the surface roughness was observed as compared to the 325 nm light. These results indicate that even wavelengths above 325 nm can cause surface roughness improvements without notably changing the structure of the photoresist. Keywords: near-field etching; organic photoresists; surface

• , there have been efforts to reduce the usage of the rare-earth material CeO2 used in the chemical slurry of CMP [8]. So in order to achieve SR reduction without the use of CMP methods, a novel approach, called near-field etching, has been introduced. This fine-tuning technique has previously proven to be