Microstructural Studies Unit

We use a mixture of imaging techniques to characterise materials including both in-lens and out-lens secondary and backscatter electron detection alongside complementary X-ray microanalysis techniques including energy dispersive spectroscopy (EDS or EDX), wavelength dispersive spectroscopy (WDS) and electron backscatter diffraction (EBSD) for advanced characterisation.

Are the techniques destructive?

SEM, EDS, WDS and EBSD are potentially non-destructive techniques depending on the samples – some material needs a conductive sputter coating or modification for observation via an electron beam.

Our newest SEM can hold samples much larger than traditional SEM samples due to a large chamber design, thus lowering the need to cut samples down to size.

TEM/STEM requires advanced sample preparation resulting in a significant change to the sample.

Minimum detectable concentration of an element

The limit of detection for EDS (for most elements) is 0.1 weight % and for WDS it is 0.02 weight %, but it does vary with the atomic number of the element and the nature of the material it is in. Typically, EDS analysis error is quoted as being ±2% relative for major components.

As each problem is unique our fees will vary depending upon:

• The analysis techniques required
• The level of analysis or information required
• The difficulty of sample preparation
• Sample type and sample number.

We can provide hourly prices on request, but we can’t give specific quotes until we have discussed your needs. However, an initial discussion with our Laboratory Manager will be free of charge and then a formal quote will be provided for your consideration.

Examples

An example of a variation in costs would be, the analysis of metallic samples in XPS where a surface composition is only required without any chemical state information can be completed faster and more easily than the analysis of insulators where chemical state information is desired.

Another example with varying costs is analysis in our Auger microscope, the elemental composition of a nanoparticle can be obtained far faster than the composition of a fracture interface fractured in vacuo.

Initial discussion

You are welcome to visit the MSSU Facility and discuss your requirements in person, or you can email our Unit Manager, James Whiting at j.d.whiting@surrey.ac.uk.

The laboratory staff will always be clear about our capability, facilities, analysis timescale and the results you can expect from the analysis.

Detailed quote is given

If it is decided to go ahead with an investigation, a description of the proposed work and a detailed quote will be sent to you for approval.

Despatching your samples

Samples should be contained in a sealable bag or container for transport to avoid contamination. Samples should be clearly labelled individually with a number or other reference if they are sent in a batch.

Typically, SEM samples are less than 30 mm diameter, but our newest SEM can hold much larger specimens. Please talk to one of our technicians for more information. 

You can arrange to bring the samples here to the Laboratory in person, or send them to us by post at:

FAO James Whiting

FEPS-SOE,

University of Surrey,

Guildford,

Surrey,

GU2 7XH

The analysis

Samples can be precision cut, mounted in a range of materials (Bakelite thermoset plastic, epoxy resin, acrylic), gold sputter coated, carbon coated, ground and polished to a sub-micron finish suitable for microscopy (and EBSD if required) and electropolishing.

Delivery time

Typically, analysis is completed within one to two working weeks from when the sample(s) is/are received. Faster turnaround can be discussed with our staff and may be possible if a quicker delivery of results is required.

Receiving your data and confidentiality

Once the analysis is complete the data that is collected is considered to be your property and is confidential. A copy will be sent to you and the original files can either be archived for up to two years or deleted at your request. Your samples (and excess material) can be returned should you require them via Parcelforce post. Any written or printed notes will be shredded after the completion of the work. All samples will be stored securely and can be stored in a locked cupboard upon request.