What is Transmission Electron Microscopy (TEM)?

Transmission electron microscopy (TEM) utilises a beam of electrons to transmit through an ultra thin specimen. The interaction between the transmitting electrons and the specimen leads to the generation of several types of signals regarding structural and chemical characteristics of the specimen material.

TEM is capable of performing multiple analyses in micro/nano-scale volumes: observing structural features as small as a single column of atoms, determining crystalline structure of nano/micro-scale objects, and determining chemical compositions as well as chemical bonding structure.

Instrument

Philips CM20 TEM
(200kV, LaB6 filament)

Functions include

• bright field (BF) imaging
• selected area diffraction (SAD)
• convergent beam electron diffraction (CBED)
• dark field (DF) imaging
• TEM-EDX chemical analysis

Sample Preperation Instruments

Gatan 691 Precision Ion Polishing System (PIPS) prepares metal and ceramic samples be using low-angle and double-side Ar-ion beam milling.

We are especially capable of preparing TEM thin foils of

• cross-sectional and plane-view of coatings, e.g. metal nitrides, diamond-like carbon, plasma nitride surfaces;
• multiphase metallic alloys, eg nickel and cobalt-superalloys, tool steels, cemented carbides
• glass/ceramic/metallic fibres, particles
• special surface samples, eg tribological surfaces for friction/wear mechanisms, oxidised surfaces for oxidation kinetics study, and corrosion failure analysis

FEI Quanta 3D FIB-FEG/ESEM (FIB-SEM) is a newly purchased state-of-the-art instrument. One of its special applications is the in-situ preparation of thin cross-sectional TEM foils under SEM observation. FIB-SEM is the latest TEM preparation technique for materials of special shapes, including sharp blades.knives/needles, thin fibres, coating and thin films and worn/oxidised surfaces.

Electro-chemical polishing preparation of thermal-sensitive metallic samples is available vs external collaboration.

Cases of Application

• Structural characterization of PVD coatings, such as TiN, CrN, DLC, nano-multilayers, and nanocomposites
• Wear mechanisms and Tribofilm formation of hard wear-resistant coatings
• Hardened martensitic/bainitic steels
• Long-term 700.C aged Nimonic 263 superalloy
• Al-Si-K-O glass fibre
• Multi-wall carbon nano-tubes (MWCNT)
• Thermal barrier coatings

To find out more about our TEM or any other equipment you can contact us on 0114 225 3500 or email MERI@shu.ac.uk