INTRODUCTION
The Scanning Electron Microscope (SEM, uses a beam of electrons instead of a beam of light to form an enlarged image of the surface object. It's a tool that allows observation and surface characterization of inorganic and organic solids. It has a great depth of field, which allows focus the sample.
The SEM is equipped with different detectors, which include: the secondary electron detector for high-resolution images SEI (secondary Electron Image), backscattered electron detector allows imaging of composition and surface topography BEI (backscattered Electron Image), and an energy dispersive detector EDS (Energy Dispersive Spectrometer) can collect X-rays generated by the sample and perform analysis semi-quantitative and distribution of elements on surfaces.
It can realize morphological studies of different materials from private companies or developed by scientific researchers and analyze the images obtained. SEM mainr utilities are high resolution (~ 1 nm), the great depth of field that gives three-dimensional look to images and simple sample preparation.
The sample preparation is relatively simple, the main features are: solid sample, conductor. Case contrary, the sample is coated with a layer of coal or a thin layer of a metal like gold to give conductive properties to the sample. Otherwise, the non-conductive samples are working in a low vacuum mode.
The applications of Scanning Electron Microscopy are varied, ranging from the petrochemical industry, polymer, ceramic, metallurgy to forensic medicine.
EQUIPMENT
1. Scanning Electron Microscope Field Emission Model 200 Nova NanoSEM FEI Company
Features
- 1nm of Resolution 30 kV, 1.5 nm 10 kV (LV).
- High Voltage 200 V a 30 kV.
- Modes: High Vacuum for conductive samples, Low Vacuum for semi and non-conductive samples.
- Detectors: Secondary, Backscattered and STEM (it combines SEM and TEM).
- EDS System.
2. System Energy Dispersive Microanalysis X-ray (EDS or EDX) Oxford INCA X-Sight Model.
The Nova NanoSEM200 is coupled with a microanalysis system Oxford INCA X-Sight Model.
SERVICES
This laboratory offers studies of morphology and elemental analysis (qualitative and semiquantitative) by energy dispersive spectroscopy (EDS) to surfaces of solid samples and determination of coating thickness, identification of contaminants in electronics, metals, ceramics, etc.
- Surface Morphological analysis by secondary electron image (SE) and analysis of composition and topography using backscattered electron image (BSE).
- Morphological and chemical analysis: a) conducting materials in high vacuum mode, b) non-conductive materials in low vacuum mode and c) transmission mode (STEM).
- Medium and high resolution up to 500,000 X magnification and 1 nm resolution.
- EDS elemental analysis (it can identify elements from 1% wt, from carbon to einsteinium).
- Determination of particle size.
- Determination of coating thickness (in most cases the samples require a cross-section, to be polished and chemically attacked).
- Failure analysis of materials in general.
- Determination of elemental contaminants in solid materials (ceramics, metals, polymers, electronic devices, coatings, etc.).
- X-ray mapping to determine the distribution of elements.
- Study of interface materials, assessment of damage materials.
- Comparison of morphological and chemical composition of raw materials, finished products, etc.
