Ceramics Products
Highly-Oriented Pyrolytic Graphite (HOPG)
More intense, efficient x-rays and neutron beams
Made of highly-oriented forms of high-purity pyrolytic graphite, Momentive Technologies graphite monochromators are shown to diffract X-rays and neutrons with greater efficiency than any other competitive material. Offering the lowest mosaic spread available, Momentive Technologies HOPG materials are excellent for beam conditioning in neutron and x-ray crystal-based optics as monochromators, analyzers or filters.
Features and Benefits
- Ultra-high purity completely prevents unwanted absorption of X-ray and neutron beams
- Lowest mosaic spread allows the narrowest wavelength range selections for X-ray and neutron beams
- Single-bent focusing monochromators using graphite (in testing) have shown yields up to 3X more than lithium fluoride at equivalent resolution
Crystals can be customized for specific mosaic spread ranges, sizes and geometries (flat, single-bent and double-bent shapes) to meet any application requirements, and our Momentive Technologies engineering experts can custom design solutions for specific or unique applications.
The European Physical Journal Conferences
The excellent performance of highly oriented pyrolytic graphite (HOPG) as monochromator, analyzer and filter material for neutron instrumentation was discovered more than 50 years ago. Even though HOPG has been in use for a long time, there is still room for improvements regarding its optimized use in neutron beam conditioning. The features of a novel concept called POSI based on careful x-ray characterization of the HOPG crystals and on proven mounting and focusing technologies show that the efficiency of HOPG monochromators can be increased while decreasing complexity and cost.
Potential Applications
- X-ray diffraction
- Neutron scattering and diffraction
- Scanning tunneling microscopy for calibration and substrates
Physical Properties of HOPG at 300K
|
d-spacing (002) (A} |
3.355-3.359 |
|
|
Density (g/cm3} |
2.255-2.265 |
|
|
|
// (002) |
1 (002) |
|
Thermal Conductivity (W /m·K) |
1600-2000 |
80 |
|
Thermal Expansion (10-6 /°C} |
-1 |
20 |
|
Electrical Resistivity (ohm·cm} |
3.5-4.5×10-5 |
0.15-0.25 |
HOPG Standard Grades and Dimensions
| Grade | X-ray mosaic spread (°) | Maximum size (mm) | |
|---|---|---|---|
|
ZYA-N |
0.35-0.45 |
50X75, 60×60 |
|
|
ZYA |
0.3-0.5 |
6 |
50X75, 60×60 |
|
ZYB-N |
0.55-0.75 |
6 |
50X75, 60×60 |
|
ZYB |
0.5-1.0 |
6 |
50X75, 60×60 |
|
ZYH |
1.0-5.0 |
12 |
60×80, 75X75 |
The information provided in these charts is for informational purposes only. It is not a product or material recommendation and it is shared with you on the express condition that you will use your own expertise and professional judgment in applying any information to a specific use case or need. This is general information only, the validity of which may be affected by individual factors that are unknown to Momentive Technologies. It is the responsibility of those using this information to ensure appropriate interpretation and application is undertaken with regards to any specific situation.
