Monitoring Nanoscale Changes using NTEGRA
Co. was established in 1991 with the purpose to apply all accumulated
experience and knowledge in the field of nanotechnology to supply researchers
with the instruments suitable to solve any possible task laying in nanometer
scale dimensions. The company NT-MDT was
founded in Zelenograd - the center of Russian Microelectronics. The products
development are based on the combination of the MEMS technology, power of modern
software, use of high-end microelectronic components and precision mechanical
parts. As a commercial enterprise NT-MDT Co.
exists from 1993.
Electrochemical (EC) technologies attract constantly rising interest because
it is the way for controlled modifications of the surface even with atomic
precision. EC deposition is a widely used approach for creation of thin metal
films with unique properties. On the other hand EC dissolution allows imitation
and study of corrosion processes.
Monitoring Nanoscale Changes using NTEGRA
probe microscopy i.e. Atomic Force Microscopy (AFM) and Scanning Tunneling
Microscopy (STM) techniques open up the possibility to monitor the nanometer
scaled changes occurring at the surface during an EC modification. With the NTEGRA
nanolaboratory one can run various EC experiments in highly specialized
As an example the imagesin Figure 1 shows that the external magnetic field
(MF) strongly influences the Cu deposition process. Due to magneto-hydrodynamic
(MHD) Electro-deposition Electro-deposition + convection and some other effects
of interaction of ions with external MF the electrodeposition occurs much
Figure 1. AFM images of copper films electro-deposited
on Au (111) without magnetic field (a1) and in magnetic field (B = 0.1 T) (a2).
Scans were obtained by using CSG01 probes. The in situ AFM investigations were
performed with the NTEGRA Aura setup in the MFM configuration. Scans size 2x2 µm.
Figure 2 demonstrate the possibilities of STM. During Cu electro-deposition
it is allowed to see the formation and destruction of a lattice with the copper
adatoms and the sulfate anions. As a result, the Cu monolayer replaces the
sulfate anions. The in situ STM investigations were performed with the NTEGRA
setup designed for electrochemical measurements.
Figure 2. STM images of the under potential deposition
(UPD) of copper on Au (111) in sulfate solution before negative shifting the
sample potential (b1) and afterwards (b2). After Fourier filtration (b3, b4),
it is obvious that negative shifting leads to the replacement of sulfate anions
by Cu adatoms: atomic structure typical for sulfate ( √3 x √3)R30°
changes to structure (1 x 1) typical for pseudo morphic Cu monolayer. Scans
size 30 x 30 nm.
EC cell for STM and AFM experiments in controlled environment provides thermostabilization.
Hermetic cell is optionally available.
Bipotentiostat is a computer-controlled module for electrochemical experiments
in potentiostatic, potentiodynamic and galvanostatic modes.
AURA is a Scanning Probe Microscope for studies in the conditions of controlled
environment and low vacuum. The Q-factor of the cantilever in vacuum increases,
thus gaining the sensitivity, reliability and accuracy of "probe-sample" light
forces measurements. At that, the change from atmosphere pressure to 10-2
Torr vacuum provides the tenfold gain of Q-factor.
By further vacuum pumping, Q-factor reaches its plateau and changes insignificantly.
AURA presents the optimal "price/quality" ratio: comparing to the high-vacuum
devices it needs much less time - only one minute - to get the vacuum that is
needed for the tenfold Q-factor increase. At the same time the system is compact
and easy to operate and maintain. As the NTEGRA
platform product, NTEGRA
AURA has built-in closed loop control for all the axes, optical system with
1 µm resolution and ability to work with more than 40 different AFM methods.
AURA setup in the MFM configuration allows to perform EC experiments in
external magnetic field.
Conventional High Resolution AFM "Golden" Silicon Probes (CSG01) for contact
mode are available with different coatings (Au, Al, PtIr, TiN, Au, diamond doped
conductive e.t.c.) and tipless. Probes without any coating and for non-contact
modes can be supplied as well.
Source: NT-MDT Co.
For more information on this source please visit NT-MDT