La Salle University
Rigaku MiniFlex 6G Powder X-ray Diffractometer
Powder X-ray diffraction (XRD) identifies the crystalline structure of materials. It generates X-rays onto a powdered sample and measures how the X-rays are diffracted by the crystalline structure. The diffracted X-rays create a fingerprint of the material’s crystal structure.
What types of samples can be analyzed?
This instrument is used for solid, crystalline materials that can be ground into a powder. XRD is not suitable for liquids or non-crystalline materials.
Common sample types include:
- Rocks and minerals
- Soils and clays
- Metals and alloys
- Industrial materials (cements, ceramics, powders)
How are samples prepared for analysis?
Samples must be dry and finely ground into a uniform powder. We have mortars, pestle, and acetone for grinding non-toxic samples if needed, although additional preparation time will be required. Powders can be packed into a sample holder, or dropped when mixed with acetone onto a zero background holder. Prepare to bring approximately 2 to 5 g of sample per sample holder.
How long does it take to analyze one sample?
Typically, a sample can take anywhere from 5-30 minutes to analyze, depending on the required resolution of the data. A total of six samples can be loaded at a time. A minimum 1 hour session is recommended for each visit.
Topcon SM300 Scanning Electron Microscope with iXRF Energy Dispersive X-ray Spectroscopy
What is this instrument?
The Topcon SM300 is a scanning electron microscope (SEM) that uses a focused beam of electrons to create highly magnified images of a sample’s surface. It is paired with energy dispersive X-ray spectroscopy (EDS), which can identify elements such as iron, silicon, or lead, present in a sample. The SEM tells you what the sample looks like, while the EDS tells you what it’s made of.
What types of samples can be analyzed?
Our SEM/EDS works best with solid materials that can fit on our sample stubs that have a diameter of ~12.7 mm. Features of interest are also best to examine if they are on the micrometer scale. Samples must be dry and stable in a vacuum. Non-conductive materials may require coating. Large, wet, or soft samples are not suitable without special preparation. Common sample types include:
- Rocks and minerals
- Metals and alloys
- Soil and dust particles
- Microplastics and particulates
- Ceramics and building materials
- Small fragments of solid materials
Grayscale microscope images of the sample surface can be produced. EDS can also perform point, line, and area elemental analyses on samples and produce elemental maps. In addition, EDS is capable of semi-quantitative elemental analysis.
How are samples prepared for analysis?
Samples should be dried and mounted onto a sample stub with adhesive carbon tape. Non-conductive samples can be coated with a conductive gold coating on-site. Note that the gold coating may interfere with EDS analyses of metals of interest. We cannot accommodate other sample preparation methods for external users at this time. However, external users may request sample stubs in order to prepare their samples in advance at their own institutions (i.e. carbon coating or critical point drying for biological samples; shipping charges may apply, but pickup is also available).
How long does it take to analyze one sample?
Budgeting at least 40 minutes per sample is recommended, including imaging and basic elemental analysis. Analysis time may vary depending on uniformity of sample and whether you want to collect elemental maps on your samples. You may also need to account for 1 hour of instrument start-up and shut-down time total when scheduling instrument use, or schedule accordingly such that the trained La Salle user can provide support for instrument start-up and shut-down. You will not be charged for instrument start-up and shut-down time, but a minimum 2.5 hour session is recommended per visit.