The laboratory of microstructural characterisation of nanostructures comprises various characterization techniques to optimize the physical-chemical nanostructures.
X-ray diffractometer to determine growth, crystal structure, thickness, density,roughness and network parameters for thin layers and superstructures.
We also have surface techniques such as the XPS-AES, very sensitive and nondestructive to provide quantitative information on all elements and their chemical state, except for hydrogen and helium. Indicated for the characterization of coatings and oxidation processes study, corrosion and adsorption.
The vibrating sample magnetometer (VSM) for magnetic characterization of materials.
XPS / XPS – AUGER / KRATOS / AXIS Ultra DLD
X-ray photoelectron spectroscopy (XPS), also known as ESCA (electron spectroscopy for chemical analysis) provides both elemental and chemical state information virtually without restriction on the type of material which can be analysed. The sample is illuminated with x-rays – monochromatic or unfiltered Al Kα or Mg Kα – and photoelectrons are emitted from the surface. The kinetic energy of these emitted electrons is characteristic of the element from which the photoelectron originated. The position and intensity of the peaks in an energy spectrum provide the desired chemical state and quantitative information.
The strength of XPS is its ability to assess the nature and the chemical state of the surface atoms , giving information in a layer up to 5 nm (4-20 atomic layers ) deep.
The sample is irradiated with a monochromatic beam of X -rays ( XPS) or electron (Auger ) and the emission energy of the photoelectrons is analyzed.
The area that can be analyzed by the electron beam and X-ray ranges from 50 nm to 900 mm in diameter. In a monolayer , sensitivity can be obtained to 0.1 % . This value corresponds to 1012 – 1013 atoms/cm2 or 10-15 – 10-16 g in the analyzed volume .
In addition, this machine has an ion beam that combines its high surface sensiblilidad with ion etching ( ion -etching ) , so that the chemical composition is obtained as a function of depth. This occurs because the emission of photoelectrons obtained by exciting atoms in a monochromatic primary source ( Mg K.alpha , 1253.6eV ) or ( Al K.alpha , 1486.6eV ) , is a characteristic of the electronic state of the surface atoms .
XPS technique combined with Auger spectroscopy yields the spatial distribution of elemental chemical composition (line profiling or mapping) . This technique is useful in a range of physical tests , for example , products of oxidation / corrosion , adsorbed species , and processes thin film growth . Insulating analysis is possible with Kratos Axis Ultra .
X-ray diffractometer (XRD) / Bruker / D8 Advance
The XRD is basic for the determination of the direction of growth technique, the crystal structure, thickness, density, roughness and network parameters.
This equipment includes goniometers that control the direction of incidence of X-rays on the sample, as well as other accessories that allow measurement of small edges with high resolution. These features are necessary to make a structural study in thin layers and superlattices.
With this equipment it is possible to obtain spectra at different points of the surface, obtaining maps of the structural properties.
Vibrating Sample Magnetometer (VSM) / ADE Technologies / EV7
Magnetic measurements, such as hysteresis and minor loops, IRM and DCD RemanenceLoops, SFD and graphics, Delta M, Delta M and Henkel and Angular and ACRemanence Loops, temperature scans and measures the decay in time.
Ultra high sensitivity (noise <0.5 μemu), also with temperature control systeminstalled.
Control real-time field with a resolution of 0001 Oe.
High-field resistive magnets, up to 2.2 T.
Temperature range: 77 K, 100 – 1000 K.
Hysteresis quick action: 2-5 minutes.
Automatic measurement of magnetic parameters for industrial applications.