scholarly journals FABRICACIÓN DE PUNTAS DE FIBRAS DE CARBONO PARA MICROSCOPÍA DE SONDA DE BARRIDO

2017 ◽  
Vol 22 (1) ◽  
pp. 17
Author(s):  
Kevin Villegas ◽  
Abel Gutarra
Keyword(s):  
Carbon Fiber ◽  
Anodic Dissolution ◽  
Base Material ◽  
Scanning Tunneling ◽  
Material Base ◽  
Additional Advantage ◽  
Atomic Force ◽  
Palabras Clave ◽  
Great Resolution ◽  
Initial Results

Los microscopios de Fuerza Atómica (AFM) con sonda diapasón requieren puntas muy agudas y livianas para obtener imágenes topográficas de gran resolución. Por otro lado, los microscopios de Efecto Túnel (STM) necesitan puntas agudas y conductoras. Ambos requerimientos pueden ser obtenidos usando fibras de carbono como material base para la fabricación de las puntas, con la ventaja adicional de ser un material con bajo nivel de oxidación. En este trabajo se presentan algunos resultados iniciales de la técnica de disolución anódica que ha permitido obtener puntas de carbono de rango nanométrico. La celda electroquímica consistió en la fibra de carbono como ánodo (7m de diámetro), un anillo de platino de 2mm de diámetro como cátodo y KOH como electrolito. Una gota del electrolito se suspendió del anillo de platino para posteriormente introducir la fibra dentro de la gota. La polarización de la celda se obtuvo por medio de una interfase electroquímica en el modo de crono-amperómetro, el cual permitió registrar las curvas corriente-tiempo para diferentes voltajes escalón. Se encontraron correlaciones entre la forma final de la punta y la molaridad del electrolito, voltaje anódico, tiempo de disolución y profundidad de inmersión de la punta en el electrolito. Por medio de microscopía electrónica de barrido se observó que se pueden obtener puntas con diámetros menores a 70 nm de manera reproducible. Palabras clave.- Fibra de carbono, Punta nanométrica, Crono-amperometría.. ABSTRACTThe Atomic Force Microscope (AFM) using a tuning fork as probe requires very sharp and light tips for obtaining topographic images with great resolution. On the other hand, Scanning Tunneling Microscopes (STM) needs sharp and conducting tips. Both requirements can be achieved using carbon fiber as the base material for the fabrication of the tips, with the additional advantage of being a material with a very low tendency to oxidize. In this work some initial results of the anodic dissolution technique are presented, which has permitted us to obtain the apex size of the tips in the nanometer scale. The electrochemical cell consists of the carbon fiber as the anode (7m diameter), a 2mm diameter Platinum ring as the cathode and Potassium Hydroxide as the electrolyte. A drop of the electrolyte is deposited on the Platinum ring and after that the carbon fiber is introduced into the drop. The polarization of the cell was obtained using a Potentiostat in Chrono-Amp mode, which permitted us to register Current vs. Time graphs for different values of potential applied. Correlations between the shape of the final tip and the molarity of the electrolyte, anodic potential, time for the anodic dissolution and the length of the carbon fiber beneath the air/electrolyte interface were found. Using Scanning Electron Microscopy, it was observed that tips with diameter lower than 70 nm can be obtained in a reproducible way.. Keywords.- Carbonfibre, Nanometer tip apex size, Chrono-amp..

Scanning tunneling microscopy and atomic force microscopy: New tools for biology

1989 ◽  
Vol 47 ◽  
pp. 778-779
Author(s):  
CE Bracker ◽  
P. K. Hansma
Keyword(s):  
Physical Property ◽  
Scanning Probe ◽  
Scanning Tunneling ◽  
Small Scale ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
New Family ◽  
Small Probe ◽  
Atomic Force ◽  
Transmission Electron

A new family of scanning probe microscopes has emerged that is opening new horizons for investigating the fine structure of matter. The earliest and best known of these instruments is the scanning tunneling microscope (STM). First published in 1982, the STM earned the 1986 Nobel Prize in Physics for two of its inventors, G. Binnig and H. Rohrer. They shared the prize with E. Ruska for his work that had led to the development of the transmission electron microscope half a century earlier. It seems appropriate that the award embodied this particular blend of the old and the new because it demonstrated to the world a long overdue respect for the enormous contributions electron microscopy has made to the understanding of matter, and at the same time it signalled the dawn of a new age in microscopy. What we are seeing is a revolution in microscopy and a redefinition of the concept of a microscope.Several kinds of scanning probe microscopes now exist, and the number is increasing. What they share in common is a small probe that is scanned over the surface of a specimen and measures a physical property on a very small scale, at or near the surface. Scanning probes can measure temperature, magnetic fields, tunneling currents, voltage, force, and ion currents, among others.

The atomic-force microscope and its future in biology

1993 ◽  
Vol 51 ◽  
pp. 704-705
Author(s):  
Jean-Paul Revel
Keyword(s):  
Silicon Nitride ◽  
Laser Beam ◽  
Atomic Force Microscope ◽  
Scanning Tunneling Microscope ◽  
Point Of View ◽  
Scanning Tunneling ◽  
Close Relative ◽  
Tunneling Microscope ◽  
Atomic Force ◽  
Sharp Point

The last few years have been marked by a series of remarkable developments in microscopy. Perhaps the most amazing of these is the growth of microscopies which use devices where the place of the lens has been taken by probes, which record information about the sample and display it in a spatial from the point of view of the context. From the point of view of the biologist one of the most promising of these microscopies without lenses is the scanned force microscope, aka atomic force microscope.This instrument was invented by Binnig, Quate and Gerber and is a close relative of the scanning tunneling microscope. Today's AFMs consist of a cantilever which bears a sharp point at its end. Often this is a silicon nitride pyramid, but there are many variations, the object of which is to make the tip sharper. A laser beam is directed at the back of the cantilever and is reflected into a split, or quadrant photodiode.

Development of the UHV-STM

1990 ◽  
Vol 48 (1) ◽  
pp. 322-323
Author(s):  
M. Iwatsuki ◽  
S. Kitamura ◽  
A. Mogami
Keyword(s):  
Surface Science ◽  
Real Space ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Great Promise ◽  
Force Microscopy ◽  
Atomic Force ◽  
Stm Image ◽  
Surface Construction ◽  
Very High

Since Binnig, Rohrer and associates observed real-space topographic images of Si(111)-7×7 and invented the scanning tunneling microscope (STM),1) the STM has been accepted as a powerful surface science instrument.Recently, many application areas for the STM have been opened up, such as atomic force microscopy (AFM), magnetic force microscopy (MFM) and others. So, the STM technology holds a great promise for the future.The great advantages of the STM are its high spatial resolution in the lateral and vertical directions on the atomic scale. However, the STM has difficulty in identifying atomic images in a desired area because it uses piezoelectric (PZT) elements as a scanner.On the other hand, the demand to observe specimens under UHV condition has grown, along with the advent of the STM technology. The requirment of UHV-STM is especially very high in to study of surface construction of semiconductors and superconducting materials on the atomic scale. In order to improve the STM image quality by keeping the specimen and tip surfaces clean, we have built a new UHV-STM (JSTM-4000XV) system which is provided with other surface analysis capability.

scholarly journals Exploring Intramolecular Methyl–Methyl Coupling on a Metal Surface for Edge-Extended Graphene Nanoribbons

2021 ◽  
Vol 03 (02) ◽  
pp. 128-133
Author(s):  
Zijie Qiu ◽  
Qiang Sun ◽  
Shiyong Wang ◽  
Gabriela Borin Barin ◽  
Bastian Dumslaff ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Atomic Force Microscopy ◽  
High Resolution ◽  
Graphene Nanoribbons ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Methyl Methyl ◽  
Atomic Force ◽  
Edge Extension

Intramolecular methyl–methyl coupling on Au (111) is explored as a new on-surface protocol for edge extension in graphene nanoribbons (GNRs). Characterized by high-resolution scanning tunneling microscopy, noncontact atomic force microscopy, and Raman spectroscopy, the methyl–methyl coupling is proven to indeed proceed at the armchair edges of the GNRs, forming six-membered rings with sp3- or sp2-hybridized carbons.

scholarly journals Local analysis of semiconductor nanoobjects by scanning tunneling atomic force microscopy

2015 ◽  
Vol 1 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Natalia A. Lashkova ◽  
Nikita V. Permiakov ◽  
Alexander I. Maximov ◽  
Yulia M. Spivak ◽  
Vyacheslav A. Moshnikov
Keyword(s):  
Atomic Force Microscopy ◽  
Local Analysis ◽  
Scanning Tunneling ◽  
Force Microscopy ◽  
Atomic Force

SCANNING PROBE MICROSCOPY BASED NANOSCALE PATTERNING AND FABRICATION

COSMOS ◽  
2007 ◽  
Vol 03 (01) ◽  
pp. 1-21 ◽  
Author(s):  
XIAN NING XIE ◽  
HONG JING CHUNG ◽  
ANDREW THYE SHEN WEE
Keyword(s):  
Integrated Circuits ◽  
Scanning Probe Microscopy ◽  
Scanning Probe ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Nanoscale Patterning ◽  
Atomic Force ◽  
Probe Microscope ◽  
Molecular Manipulation

Nanotechnology is vital to the fabrication of integrated circuits, memory devices, display units, biochips and biosensors. Scanning probe microscope (SPM) has emerged to be a unique tool for materials structuring and patterning with atomic and molecular resolution. SPM includes scanning tunneling microscopy (STM) and atomic force microscopy (AFM). In this chapter, we selectively discuss the atomic and molecular manipulation capabilities of STM nanolithography. As for AFM nanolithography, we focus on those nanopatterning techniques involving water and/or air when operated in ambient. The typical methods, mechanisms and applications of selected SPM nanolithographic techniques in nanoscale structuring and fabrication are reviewed.

A Fresh Insight Into the Microcantilever-Sample Interaction Problem in Non-Contact Atomic Force Microscopy

2004 ◽  
Vol 126 (2) ◽  
pp. 327-335 ◽  
Author(s):  
Nader Jalili ◽  
Mohsen Dadfarnia ◽  
Darren M. Dawson
Keyword(s):  
Imaging Techniques ◽  
Interaction Force ◽  
Intermolecular Forces ◽  
Scanning Tunneling ◽  
Atomic Interaction ◽  
Force Estimation ◽  
Contact Mode ◽  
Distributed Parameters ◽  
Atomic Force ◽  
Insight Into

The atomic force microscope (AFM) system has evolved into a useful tool for direct measurements of intermolecular forces with atomic-resolution characterization that can be employed in a broad spectrum of applications. The non-contact AFM offers unique advantages over other contemporary scanning probe techniques such as contact AFM and scanning tunneling microscopy, especially when utilized for reliable measurements of soft samples (e.g., biological species). Current AFM imaging techniques are often based on a lumped-parameters model and ordinary differential equation (ODE) representation of the micro-cantilevers coupled with an adhoc method for atomic interaction force estimation (especially in non-contact mode). Since the magnitude of the interaction force lies within the range of nano-Newtons to pica-Newtons, precise estimation of the atomic force is crucial for accurate topographical imaging. In contrast to the previously utilized lumped modeling methods, this paper aims at improving current AFM measurement technique through developing a general distributed-parameters base modeling approach that reveals greater insight into the fundamental characteristics of the microcantilever-sample interaction. For this, the governing equations of motion are derived in the global coordinates via the Hamilton’s Extended Principle. An interaction force identification scheme is then designed based on the original infinite dimensional distributed-parameters system which, in turn, reveals the unmeasurable distance between AFM tip and sample surface. Numerical simulations are provided to support these claims.

Measurement of Plasticity Gradients with Scanning Probe Microscopy

1993 ◽  
Vol 318 ◽  
Author(s):  
James D. Kiely ◽  
Dawn A. Bonnell
Keyword(s):  
Fracture Surface ◽  
Scanning Probe Microscopy ◽  
Scanning Probe ◽  
Scanning Tunneling ◽  
Ceramic System ◽  
Force Microscopy ◽  
Metal Fracture ◽  
Atomic Force ◽  
Metal Ceramic

ABSTRACTScanning Tunneling and Atomic Force Microscopy were used to characterize the topography of fractured Au /sapphire interfaces. Variance analysis which quantifies surface morphology was developed and applied to the characterization of the metal fracture surface of the metal/ceramic system. Fracture surface features related to plasticity were quantified and correlated to the fracture energy and energy release rate.

Micromechanisms of Hydrogen-Assisted Cracking in Super Duplex Stainless Steel Investigated by Scanning Probe Microscopy

2014 ◽  
Author(s):  
Bai An ◽  
Takashi Iijima ◽  
Chris San Marchi ◽  
Brian Somerday
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Scanning Tunneling ◽  
Super Duplex Stainless Steel ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Hydrogen Assisted Cracking ◽  
Cracking Mechanisms ◽  
Localized Plastic Deformation

Understanding the micromechanisms of hydrogen-assisted fracture in multiphase metals is of great scientific and engineering importance. By using a combination of scanning electron microscopy (SEM), scanning tunneling microscopy (STM), atomic force microscopy (AFM) and magnetic force microscopy (MFM), the micromorphology of fracture surface and microcrack formation in hydrogen-precharged super duplex stainless steel 2507 are characterized from microscale to nanoscale. The results reveal that the fracture surfaces consist of quasi-brittle facets with riverlike patterns at the microscale, which exhibit rough irregular patterns or remarkable quasi-periodic corrugation patterns at the nanoscale that can be correlated with highly localized plastic deformation. The microcracks preferentially initiate and propagate in ferrite phase and are stopped or deflected by the boundaries of the austenite phase. The hydrogen-assisted cracking mechanisms in super duplex stainless steel are discussed according to the experimental results and hydrogen-enhanced localized plasticity theory.

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