Tag: conductive AFM tip

Flexible Robust and High‐Density FeRAM from Array of Organic Ferroelectric Nano‐Lamellae by Self‐Assembly

Ferroelectric memories are endowed with high data storage density by nanostructure designing, while the robustness is also impaired. For organic ferroelectrics favored by flexible memories, low Curie transition temperature limits their thermal stability.*

In their article “Flexible Robust and High‐Density FeRAM from Array of Organic Ferroelectric Nano‐Lamellae by Self‐Assembly “ Mengfan Guo, Jianyong Jiang, Jianfeng Qian, Chen Liu, Jing Ma, Ce‐Wen Nan and Yang Shen demonstrate that a ferroelectric random access memory ( FeRAM ) with high thermal stability and data storage density of ≈60 GB inch−2 could be achieved from an array of edge‐on nano‐lamellae by low‐temperature self‐assembly of P(VDF‐TrFE).*

The self‐assembled P(VDF‐TrFE) described in the article exhibits high storage density of 60 GB inch−2 as a prototype of flexible FeRAM. The authors experimentally determine the self‐assembled FeRAM stored data more robustly, with temperature endurance enhanced over 10 °C and reliable thermal cycling ability. The article shows a novel path to address the thermal stability issues in organic FeRAMs and presents a detailed analysis about the origin of enhanced performance in aligned P(VDF‐TrFE). *

NanoWorld Arrow-CONTPt AFM probes with a conducting Pt/Ir coating were used for the Piezoresponse Force Microscopy ( PFM ) measurements described in this article.

Figure 4 from “Flexible Robust and High‐Density FeRAM from Array of Organic Ferroelectric Nano‐Lamellae by Self‐Assembly” by Mengfan Guo et al.:
Enhanced thermal stability in SA P(VDF‐TrFE). a–c) PFM images of data stored in self‐assembled film at a) 25 °C and b) 90 °C, as well as c) numeric figure of residual area of reversal domains as a function of elevated temperature in a SA film (blue) and a NSA film (red). d) Numeric figure of residual area of reversal domains as a function of thermal cycles in a SA film (blue) and a NSA film (red). Scale bars: 200 nm.

*Mengfan Guo, Jianyong Jiang, Jianfeng Qian, Chen Liu, Jing Ma, Ce‐Wen Nan, Yang Shen
Flexible Robust and High‐Density FeRAM from Array of Organic Ferroelectric Nano‐Lamellae by Self‐Assembly
Advanced Science, Volume6, Issue6, March 20, 2019, 1801931
DOI: https://doi.org/10.1002/advs.201801931

Please follow this external link to read the full article: https://onlinelibrary.wiley.com/doi/full/10.1002/advs.201801931

Open Access: The article « Flexible Robust and High‐Density FeRAM from Array of Organic Ferroelectric Nano‐Lamellae by Self‐Assembly » by Mengfan Guo, Jianyong Jiang, Jianfeng Qian, Chen Liu, Jing Ma, Ce‐Wen Nan and Yang Shen 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/.

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/.