Tag: Arrow AFM probe

Launching of hyperbolic phonon-polaritons in h-BN slabs by resonant metal plasmonic antennas

Launching and manipulation of polaritons in van der Waals materials offers novel opportunities for applications such as field-enhanced molecular spectroscopy and photodetection.*

Particularly, the highly confined hyperbolic phonon polaritons (HPhPs) in h-BN slabs attract growing interest for their capability of guiding light at the nanoscale. An efficient coupling between free space photons and HPhPs is, however, hampered by their large momentum mismatch.*

In the article “Launching of hyperbolic phonon-polaritons in h-BN slabs by resonant metal plasmonic antennas” P. Pons-Valencia, F. J. Alfaro-Mozaz, M. M. Wiecha, V. Biolek, I. Dolado, S. Vélez,P. Li, P. Alonso-González, F. Casanova, L. E. Hueso, L. Martín-Moreno, R. Hillenbrand and A. Y. Nikitin show that resonant metallic antennas can efficiently launch HPhPs in thin h-BN slabs. Despite the strong hybridization of HPhPs in the h-BN slab and Fabry-Pérot plasmonic resonances in the metal antenna, the efficiency of launching propagating HPhPs in h-BN by resonant antennas exceeds significantly that of the non-resonant ones.

Their results provide fundamental insights into the launching of HPhPs in thin polar slabs by resonant plasmonic antennas, which will be crucial for phonon-polariton based nanophotonic devices.*

A commercial s-SNOM setup in which the oscillating (at a frequency Ω≅270kHz) metal-coated (Pt/Ir) AFM tip (NanoWorld ARROW-NCPt) was illuminated by p-polarized mid-IR radiation, was used.*

Figure 4 from “Launching of hyperbolic phonon-polaritons in h-BN slabs by resonant metal plasmonic antennas” by P. Pns-Valencia et al. : Near-field imaging of the HPhPs launched by the gold antenna. a Schematics of the s-SNOM setup. b Illustration of antenna launching of HPhPs. The spatial distribution of the near-field (shown by the red and blue colors) is adapted from the simulation of Re(Ez). c Topography of the antenna. d Simulated near-field distribution, |E(x, y)|, created by the rod antenna on CaF2 (the field is taken at the top surface of the antenna). Scale bars in c, d are 0.5 μm. e, h Experimental near-field images. f, i Simulated near-field distribution |Ez(x, y)| (taken 150 nm away from the h-BN slab). g, j Simulated near-field distribution |Ez(z, y)| taken in the cross-section plane along the center of the rod antenna. In e–g ω = 1430 cm−1, while in h–j ω = 1515 cm−1. The scale bars in e–i are 2 μm and in g, j are 0.1 μm (vertical) and 0.5 μm (horizontal). The length of the antenna in all panels is L = 2.29 μm

Figure 4 from “Launching of hyperbolic phonon-polaritons in h-BN slabs by resonant metal plasmonic antennas” by P. Pons-Valencia et al. :
Near-field imaging of the HPhPs launched by the gold antenna. a Schematics of the s-SNOM setup. b Illustration of antenna launching of HPhPs. The spatial distribution of the near-field (shown by the red and blue colors) is adapted from the simulation of Re(Ez). c Topography of the antenna. d Simulated near-field distribution, |E(x, y)|, created by the rod antenna on CaF2 (the field is taken at the top surface of the antenna). Scale bars in c, d are 0.5 μm. e, h Experimental near-field images. f, i Simulated near-field distribution |Ez(x, y)| (taken 150 nm away from the h-BN slab). g, j Simulated near-field distribution |Ez(z, y)| taken in the cross-section plane along the center of the rod antenna. In e–g ω = 1430 cm−1, while in h–j ω = 1515 cm−1. The scale bars in e–i are 2 μm and in g, j are 0.1 μm (vertical) and 0.5 μm (horizontal). The length of the antenna in all panels is L = 2.29 μm

*P. Pons-Valencia, F. J. Alfaro-Mozaz, M. M. Wiecha, V. Biolek, I. Dolado, S. Vélez,P. Li, P. Alonso-González, F. Casanova, L. E. Hueso, L. Martín-Moreno, R. Hillenbrand, A. Y. Nikitin
Launching of hyperbolic phonon-polaritons in h-BN slabs by resonant metal plasmonic antennas
Nature Communications 2019; 10: 3242
doi: 10.1038/s41467-019-11143-7

Please follow this external link to read the full article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6642108/

Open Access: The paper « Launching of hyperbolic phonon-polaritons in h-BN slabs by resonant metal plasmonic antennas » by P. Pons-Valencia, F. J. Alfaro-Mozaz, M. M. Wiecha, V. Biolek, I. Dolado, S. Vélez,P. Li, P. Alonso-González, F. Casanova, L. E. Hueso, L. Martín-Moreno, R. Hillenbrand and A. Y. Nikitin is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Electrical conductivity of silver nanoparticle doped carbon nanofibres measured by CS-AFM

Composite carbon nanofibres (CNFs) are highly interesting materials which are usable in a wide array of applications e.g. electrode materials for biosensors, lithium ion batteries, fuel cells and supercapacitors.*

In their paper “Electrical conductivity of silver nanoparticle doped carbon nanofibres measured by CS-AFM” Wael Ali, Valbone Shabani, Matthias Linke, Sezin Sayin, Beate Gebert, Sedakat Altinpinar, Marcus Hildebrandt, Jochen S. Gutmann and Thomas Mayer-Gall present a study on the electrical properties of composite carbon nanofibres (CNFs) using current-sensitive atomic force microscopy (CS-AFM).*

This technique makes it possible to explore the electrical properties of single fibers and hence derive relationships between the structural features and the electrical properties.
NanoWorld AFM probes with conductive PtIr5 coated silicon tips (force constant 2.8 N m−1, length 240 μm, mean width 35 μm and a thickness of 3 μm, and tip height 10–15 μm) Arrow-EFM were used.*

The results presented in the paper show that the composite CNFs have a higher electrical conductivity than the neat CNFs and both the average diameter of the fibers and the electrical conductivity increase with an increasing AgNP content.*

Fig. 8 from “Electrical conductivity of silver nanoparticle doped carbon nanofibres measured by CS-AFM “ by Wael Ali et al.: CS-AFM analysis of CNFs processed from PAN nanofibres electrospun with different concentrations. Images show the friction and current after both stabilisation (a) and carbonisation (b) processes. The applied bias voltage was +0.15 V. The scan area was 5 × 5 μm2 with a scale bar of 1 μm.

Fig. 8 from “Electrical conductivity of silver nanoparticle doped carbon nanofibres measured by CS-AFM “ by Wael Ali et al.: CS-AFM analysis of CNFs processed from PAN nanofibres electrospun with different concentrations. Images show the friction and current after both stabilisation (a) and carbonisation (b) processes. The applied bias voltage was +0.15 V. The scan area was 5 × 5 μm2 with a scale bar of 1 μm.

*Wael Ali, Valbone Shabani, Matthias Linke, Sezin Sayin, Beate Gebert, Sedakat Altinpinar, Marcus Hildebrandt, Jochen S. Gutmann, Thomas Mayer-Gall
Electrical conductivity of silver nanoparticle doped carbon nanofibres measured by CS-AFM
RSC Adv., 2019, 9, 4553-4562
DOI: 10.1039/C8RA04594A

Please follow this external link to the full article: https://pubs.rsc.org/en/content/articlehtml/2019/ra/c8ra04594a

Open Access: The article “Electrical conductivity of silver nanoparticle doped carbon nanofibres measured by CS-AFM” by Wael Ali, Valbone Shabani, Matthias Linke, Sezin Sayin, Beate Gebert, Sedakat Altinpinar, Marcus Hildebrandt, Jochen S. Gutmann and Thomas Mayer-Gall is licensed under a Creative Commons Attribution 3.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. To view a copy of this license, visit https://creativecommons.org/licenses/by/3.0/.

Piezoelectricity of green carp scales

Today is Children’s Day in Japan and many mulit-colored carp-shaped koinobori streamers will flutter in the wind.

So it is the perfect day to share the publication “Piezoelectricity of green carp scales” by Y. Jiang et al. with you.

Piezoelectricity takes part in multiple important functions and processes in biomaterials often vital to the survival of organisms. In their publication , “Piezoelectricity of green carp scales” Y. Jiang et al. investigate the piezoelectric properties of fish scales of green carp by directly examining their morphology at nanometer levels. From the clear distinctions between the composition of the inner and outer surfaces of the scales that could be found, the authors identified the piezoelectricity to originate from the presence of hydroxyapatite which only exists on the surface of the fish scales.*

koinobori - carp streamers on children's day in Matsumoto Japan
koinobori – carp streamers in Matsumoto Japan

These findings reveal a different mechanism of how green carp are sensitive to their surroundings and should be helpful to studies related to the electromechanical properties of marine life and the development of bio-inspired materials. As easily accessible natural polymers, fish scales can be employed as highly sensitive piezoelectric materials in high sensitive and high speed devices as well as be exploited for invasive diagnostics and other biomedical implications.*

For the harmonic responses of both 1st order and 2nd order described in this publication, NanoWorld Arrow-CONTPt AFM probes were used.

FIG. 6 from “Piezoelectricity of green carp scales “ by H. Y. Jiang et al.: First and second harmonic responses of (a) domain I and (b) domain IV. The straight line fitting for the amplitude of first harmonic response of (c) domain I and (d) domain IV by applying a series of bias. NanoWorld Arrow-CONTPt AFM probes were used.
FIG. 6 from “Piezoelectricity of green carp scales “ by H. Y. Jiang et al.: First and second harmonic responses of (a) domain I and (b) domain IV. The straight line fitting for the amplitude of first harmonic response of (c) domain I and (d) domain IV by applying a series of bias.

*Y. Jiang, F. Yen, C. W. Huang, R. B. Mei, and L. Chen
Piezoelectricity of green carp scales
AIP Advances 7, 045215 (2017)
DOI: https://doi.org/10.1063/1.4979503

Please follow this external link to access the full article: https://aip.scitation.org/doi/full/10.1063/1.4979503

Open Access The article “Piezoelectricity of green carp scales” by Y. Jiang, F. Yen, C. W. Huang, R. B. Mei and L. Chen is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.