Direct observation of the dynamics of single metal ions at the interface with solids in aqueous solutions

For the AFM measurements in the article “Direct observation of the dynamics of single metal ions at the interface with solids in aqueous solutions” by Ricci, M. et al. a NanoWorld Arrow-UHFAuD AFM probe was used. Congratulations to the authors!

Figure 3 from: "Ricci, M. et al. Direct observation of the dynamics of single metal ions at the interface with solids in aqueous solutions."
Figure 3 from: “Ricci, M. et al. Direct observation of the dynamics of single metal ions at the interface with solids in aqueous solutions.“: Kinetic experiments conducted in pure water (a) show mainly two levels (arrows) when compared to Fig. 2a. Height variations are less pronounced than in RbCl solution and analysis of the surface dynamics (inset) reveals slower timescales with a relatively strong dependence on the choice of threshold. The profile shown in the inset is taken after site averaging (see e.g. Fig. 2d), hence the small height variations. More reliable results were obtained for lower threshold values (here −20 pm, see Supplementary Fig. S10). The overall ratio between the two levels visible in (a) can be changed by adjusting the pH of the water with HCl (b–g), suggesting the higher level to be related to hydration water and the lower level to reflect adsorption of H3O+, as detected by the AFM tip. For each of the pH value studied, the raw kinetic experiments (b,e) are site-averaged (c,f) as in Fig. 2d to remove the mica corrugation and imaging noise. The height distribution of the site-averaged data is then binarised automatically (d,g) depending on whether the surface height is higher or lower than the average between the surface’s highest and lowest points. The fraction of surface interpreted as covered with H3O+ (purple in d and g) changes from 55 ± 3% to 75 ± 2%. (b,e) were acquired with a same tip. The mica samples have been rinsed with the imaging solution after being cleaved and the presence of K+ ions on the surface can be neglected (concentration <10 nM). The scale bar is 3 nm in all experiments.

Abstract:
The dynamics of ions adsorbed at the surface of immersed charged solids plays a central role in countless natural and industrial processes such as crystal growth, heterogeneous catalysis, electrochemistry, or biological function. Electrokinetic measurements typically distinguish between a so-called Stern layer of ions and water molecules directly adsorbed on to the solid’s surface, and a diffuse layer of ions further away from the surface. Dynamics within the Stern layer remain poorly understood, largely owing to a lack of in-situ atomic-level insights. Here we follow the dynamics of single Rb+ and H3O+ ions at the surface of mica in water using high-resolution atomic force microscopy with 25 ms resolution. Our results suggest that single hydrated Rb+ions reside τ1 = 104 ± 5 ms at a given location, but this is dependent on the hydration state of the surface which evolves on a slower timescale of τ2 = 610 ± 30 ms depending on H3O+ adsorption. Increasing the liquid’s temperature from 5 °C to 65 °C predictably decreases the apparent glassiness of the interfacial water, but no clear effect on the ions’ dynamics was observed, indicating a diffusion-dominated process. These timescales are remarkably slow for individual monovalent ions and could have important implications for interfacial processes in electrolytes.

Maria Ricci, William Trewby, Clodomiro Cafolla, Kislon Voïtchovsky
Direct observation of the dynamics of single metal ions at the interface with solids in aqueous solutions
Nature Scientific Reports volume 7, Article number: 43234 (2017)
doi: https://doi.org/10.1038/srep43234

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This article “Direct observation of the dynamics of sigle metal ions at the interface with solids in aqueous solutions” by Ricci, M. et al. is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

Meet the NanoWorld CEO at ISPM 2018 in Tempe

The 20th International Scanning Probe Microscopy (ISPM) conference is hosted by Arizona State University this year. Meet NanoWorld CEO Manfred Detterbeck at the NanoAndMore USA booth in Tempe, Arizona from May 8 – 11, 2018.

meet NanoWorld CEO Manfred Detterbeck at International Scanning Probe Microscopy ( ISPM) 2018 in Tempe Arizona and learn about new AFM probe developments
meet NanoWorld CEO Manfred Detterbeck at ISPM 2018

 

Ferroelectric Domain Studies of Patterned (001) BiFeO3 by Angle-Resolved Piezoresponse Force Microscopy

Figure 1 from "Ferroelectric Domain Studies of Patterned (001) BiFeO 3 by Angle- Resolved Piezoresponse Force Microscopy": Patterned mesas are separated from the continuous film by lithography, as shown in the AFM topography image. (b) Schematic drawing of the atomic structure of BFO with angle-resolved polarization models. The Fe (red sphere) atom can be displaced towards twelve possible polarization orientations with respect to its centrosymmetric position. (c) AR-PFM domain map of a 1.2 × 1.2 μm2 area of unpatterned BFO film, corresponding to the black dashed area in (a). (d) The area distribution of each polarization variant according to angle relative to the [100] direction. (e) The average area of stable and meta-stable polarization variants.
Figure 1 from Seungbum Hong et al. “Ferroelectric Domain Studies of
Patterned (001) BiFeO3 by Angle-Resolved Piezoresponse Force Microscopy”:
Patterned mesas are separated from the continuous film by lithography, as shown in the AFM topography image.
(b) Schematic drawing of the atomic structure of BFO with angle-resolved polarization models. The Fe (red sphere) atom can be displaced towards twelve possible polarization orientations with respect to its centrosymmetric position. (c) AR-PFM domain map of a 1.2 × 1.2 μm2 area of unpatterned BFO film, corresponding to the black dashed area in (a). (d) The area distribution of each polarization variant according to angle relative to the [100] direction. (e) The average area of stable and meta-stable polarization variants.
NanoWorld EFM PtIr coated probes were used for the PFM measurements mentioned in this brand new publication on ferroelectric domain imaging of patterned BFO thin films in Scientific Reports.
Congratulations to the authors!
 #afmprobes #atomicforcemicroscopy #afmtips #AFM

Bumsoo Kim, Frank P. Barrows, Yogesh Sharma, Ram S. Katiyar, Charudatta Phatak, Amanda K. Petford-Long, Seokwoo Jeon, Seungbum Hong
Scientific Reports (2018) 8:20, DOI:10.1038/s41598-017-18482-9
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