Scanning Electron Microscopy (SEM)

The JEOL 7100F FEG-SEM at the Nanoscale and Microscale Research Centre

SEM at a glance

SEM is an imaging technique that uses incident electrons to generate secondary sample irradiance. This can then be detected in a variety of ways to visualise sample surfaces with high depth of field and lateral resolutions of around 1-20nm, as well as analyse the physical and chemical state of the substrate.

FIBSEM couples traditional SEM with a focused ion beam that can be used for materials processing and sample preparation (deposition, ablation, sectioning etc.) or at low beam currents, for imaging in its own right.
ESEM allows for the imaging of poorly conductive ‘uncoated’, or ‘wet’ samples that cannot be imaged in the high vacuum conditions of a traditional SEM.
Cryo-SEM allows for biological samples to be rapidly frozen, prepared and then SEM imaged. This preserves the initial substrate morphology and chemistry of the fully hydrated specimen by preventing water loss to vacuum operation.
FEGSEM uses a field emission gun electron source to generate a smaller diameter electron beam than standard thermal emission sources. This allows better spatial resolution to be achieved and makes the technique more suitable for nanostructural characterisation.

Applications of SEM

Morphological and topographical imaging
Compositional contrast imaging
Chemical analysis via energy or wavelength dispersive X-ray spectroscopy (EDS, WDS)
Dynamic macro-, micro- and nano-structural imaging under temperature, pressure and strain variations
Sample manipulation, sectioning and thinning

Scanning Electron Microscopy with cryo-handling capabilities

How does SEM work?

A fine beam of electrons is used to scan across the specimen surface in synchronism with the spot of a cathode ray tube (CRT). This incident beam leads to elastic and inelastic scattering of electrons, as well as variations of electromagnetic radiation. There are subsequently a host of secondary signals that can be detected, including secondary electrons, backscattered electrons, Auger electrons, cathodoluminescence or X-rays. In general, as the primary electron beam is rastered across a substrate, the intensity of the secondary signal will change depending on the surface morphology, chemistry, physical state etc. The contrast is seen by adjusting the brightness of the CRT spot by the amplified version of this detected signal.

Images courtesy of Vladimir Korolkov Photography and Lubrizol Ltd.

Our SEM Facilities

Hosted at the Nanoscale and Microscale Research Centre (nmRC).

Investigate sample morphology, topography and constitution using SEM

Use a focused ion beam to process samples for imaging and analysis using our FIB-SEM

ISAC grants access to multiple SEM instruments tailored to the work to be carried out

Multiple sample mounting for ESEM in water vapour, nitrogen or air.

Zeiss Crossbeam 550 (HR-CAT-SEM)

(Cryo-SEM and Cryo-FIB facilities)

The Crossbeam 550 incorporates:

Gemini optics with superb low kV performance, extremely large field of views and a complete detection system (in-lens SE-detector, chamber SE-detector, in-lens EsB detector, chamber BsD detector). Secondary electron, secondary ion detector (required for cryo imaging).
Magnetic-field free Gemini objective lens design for imaging of magnetic samples and live imaging during FIB milling without compromises. The system allows investigations of a large variety of samples including conductive, non-conductive and magnetic samples.
Highest levels of spatial resolution at low KV's: 1.4nm at 1 kV* (SE and BSE), Coincidence Point (WD 5mm): 1.8nm at 1 kV

In combination with a Focused Ion Beam (FIB) and a Gas Injection System (GIS) the platform is extended towards a workstation for advanced TEM lamella preparation, 3D Tomography and nanofabrication.

Flood gun
X2 sample holder together with SmartEPD software to achieve sub 20nm lamellae preparation (unique)
6-axis super-eucentric stage (unique)
12 position STEM holder optimised for EDS analysis
3D EBSD applicable hardware and sample holder
A four gas plus Charge Compensator, Multi GIS system has been included. Platinum, Carbon Mill(water) and Carbon precursors available.
Cryogenic system to freeze, manipulate and transfer samples into SEM, FE-SEM and Crossbeam systems. The PP3010T consist of a cryo sub-stage and anticontaminator for the SEM, a turbo pumped airlock and preparation station mounted to the SEM chamber.
Omniprobe 200 Micromanipulator with Omniprobe rotation option and omniprobe cryo liftout option
Aztec Live Advanced Ultimax 170mm (EDS) detector
Aztec HKL Advanced integrated Symmetry (EBSD) detector
Pneumatic retractable STEM detector with annular detection diode design. Diode consists of a central segment (BF) Normal dark field (DF), Oriented dark field (ODF), Annular dark field (ADF), High angle annular dark field (HAADF).

JEOL 7100F FEG-SEM

JEOL in-lens Schottky field emission source
3.0 nm resolution at 1 kV
1.2nm resolution at 30 kV
GATAN Murano Heating Stage Module with heating up to 950^oC
Oxford Instruments AZtec Energy Advanced X-max 150 EDS System for chemical characterisation
Oxford Instruments AZtec HKL Advanced EBSD System (with NordlysMax3) for crystallographic characterisation
Oxford Instruments INCA Wave 700 WDS System for high resolution elemental mapping and quantification

JEOL 7000F FEG-SEM

FEG-SEM
Oxford Instruments AZtec EDX system

Thermo Fisher (FEI) Quanta200 3D DualBeam FIB/SEM

(Cryo-SEM & ESEM facilities)

Thermal emission electron optics with dual-anode source emission geometry and through-the-lens differential pumping
High-resolution (field emission) ion optics (Magnum^TM column) with high-volume milling capabilities and an in-situ Omniprobe Model 100.7 nanomanipulator for sample milling, thinning, sectioning and lift-outs for more detailed structural SEM or TEM analysis
Quorum Technologies PP3010T Cryo-SEM Preparation System for cryogenic sample preparation and analysis, including freeze-fracture and freeze-etching
Oxford Instruments integrated INCA Energy 250 Microanalysis System for EDX elemental spectra and mapping
Gaseous secondary and backscattered electron detectors for imaging and analysis in a gaseous environment (ESEM)
Gas Chemistry technology for enhanced milling rates including selective carbon mill
High-precision specimen goniometer with 50 mm travel along the x and y axes
Automation serving unattended sectioning with full access to E-beam, I-beam, patterning and gas chemistry functionality
Tungsten metal deposition, carbon deposition, insulator enhanced etch (XeF2) and selective carbon mill gas injectors (2 fitted at one time)

Thermo Fisher (FEI) Quanta 650 ESEM

High performance imaging in three modes: High Vacuum, Low Vacuum and ESEM
Water vapour, air and nitrogen ESEM imaging modes for hydrated or non-coated samples
Deben in-situ Microtest tensile-compression stage MTEST200VT with loading up to 200N and Peltier temperature range -20^oC to 160^oC
Variable vapour pressures with peltier based temperature control for relative humidity cycling/adjustment sample freeze thaw cycling
Alemnis in-situ Nano Indenter for micropillar compression and scratch testing
Oxford Instruments X-Max -150 EDX Detector for high sensitivity chemical analysis
Peltier cooling stage for sample and humidity (gas pressure) control
High performance thermal emission SEM column with dual-anode source emission geometry
High vacuum resolution: 3.0nm @ 30kV, 8.0nm @ 3kV
Low vacuum resolution: 3.0nm @ 30kV, 10.0nm @ 3kV
ESEM resolution: 3.0nm @ 30kV

Thermo Fisher (FEI) Quanta 600 Mineral Liberation Analyser (MLA)

Combines EDS software by BRUKER and Mineral Liberation Analysis (MLA) software by JKTech/FEI that allows automated large area analysis of polished specimens to identify and quantify mineral composition and distribution
Outputs include calculated assay, elemental distribution, particle size distribution, modal mineralogy, mineral association, mineral locking etc.
Can take up to 14 polished mounts at a time, or samples up to 150mm² with automated analysis of each sample in turn
HV and LV operational modes with secondary or backscattered electron detection
Resolution reported at 3.5nm @ 30kV

JEOL JSM IT-200 SEM

Tungsten electron source capable of <10 nm resolution
Fitted with standard secondary electron (SE) and back-scatter electron (BSE) detectors for routine morphology and atomic number contrast characterisation
Low vacuum mode (< 120 Pa) for charge free imaging of non-conductive and non-vacuum compatible materials
Sample holders for mounting multiple pin-type stubs or cylindrical holders
Easy to use new interface with navigation camera using a photo of actual samples loaded into the chamber. Fitted with a chamberscope integrated into the microscope control software
Fitted with an Oxford Instruments Aztec Energy dispersive X-ray analysis (EDX) system and an Ultim-100 silicon drift detector capable of quantitative elemental analysis, X-ray mapping and line scanning and the very useful Aztec Live feature allowing real time chemical imaging.

Thermo Fisher (FEI) XL30 SEM

Standard imaging with EDX available

JEOL 6490LV SEM

Standard and low vacuum imaging with EDX and WDX available

Publications of Interest

Additive manufacture of complex 3D Au-containing nanocomposites by simultaneous two-photon polymerisation and photoreduction, Hu, Q., Sun, X.-Z., Parmenter, C. D. J., Fay, M. W., Smith, E. F., Rance, G. A., He, Y., Zhang, F., Liu, Y., Irvine, D., Tuck, C., Hague, R. & Wildman, R., Scientific Reports,7, 17150 (2017).
Interactions at the Silica–Peptide Interface: Influence of the Extent of Functionalization on the Conformational Ensemble, Sola-Rabada, A., Michaelis, M., Oliver, D. J., Roe, M. J., Colombi Ciacchi, L., Heinz, H. & Perry, C. C., Langmuir,34, 8255–8263 (2018).
Synthesis of hydroxylated group IV metal oxides inside hollow graphitised carbon nanofibers: nano-sponges and nanoreactors for enhanced decontamination of organophosphates, Astle, M. A., Rance, G. A., Fay, M. W., Notman, S., Sambrook, M. R. & Khlobystov, A. N., Journal of Materials Chemistry A,6, 20444–20453 (2018).
Y-Mars: An Astrobiological Analogue of Martian Mudstone, Stevens, A. H., Steer, E., McDonald, A., Amador, E. S. & Cockell, C. S., Earth and Space Science,5, 163–174 (2018).
Flame spheroidisation of dense and porous Ca₂Fe₂O₅ microspheres, Molinar Díaz, J., Samad, S. A., Steer, E., Neate, N., Constantin, H., Islam, M. T., Brown, P. D. & Ahmed, I., Materials Advances,1, 3539–3544 (2020).
Electric Field Induced Biomimetic Transmembrane Electron Transport Using Carbon Nanotube Porins, Hicks, J. M., Yao, Y.-C., Barber, S., Neate, N., Watts, J. A., Noy, A. & Rawson, F. J., Small, 17, 2102517 (2021).
Efficacy of antimicrobial and anti-viral coated air filters to prevent the spread of airborne pathogens, Watson, R., Oldfield, M., Bryant, J. A., Riordan, L., Hill, H. J., Watts, J. A., Alexander, M. R., Cox, M. J., Stamataki, Z., Scurr, D. J. & de Cogan, F., Scientific Reports,12, 2803 (2022).
Metallocatanionic vesicle-mediated enhanced singlet oxygen generation and photodynamic therapy of cancer cells, Sharma, B., Jain, A., Pérez-García, L., Watts, J. A., Rawson, F. J., Chaudhary, G. R. & Kaur, G., Journal of Materials Chemistry B, 10, 2160–2170 (2022).