HOPG (ZYH Grade)
Highly Oriented Pyrolytic Graphite (HOPG) and are forms of high purity Pyrolytic Graphite annealed under pressure at temperatures about 3000ºC. Its main physical characteristics (at 20ºC) are summarized in the following Table.
|
interlayer distance (002) |
3.354-3.358 Å |
|
density |
2.24-2.25 g/cm3 |
|
thermal conductivity parallel (002) |
1700+/-100 W/(m·K) |
|
thermal expansion parallel (002) |
-1x10-6 K-1 |
|
electrical conductivity parallel (002) |
2.1+/-0.1x106 [(W·m)-1] |
|
purity |
> 99.99 % |
HOPG crystals are used as monochromators and focusing optics for x-ray beams. Some typical parameters of the HOPG optics are shown in the following Table.
|
Energy range |
2-120 keV |
|
Reflection coefficient |
15-50% |
|
Integral reflectivity |
up to 0.01 rad |
|
Rocking curve width |
0.3º-0.4º |
|
Solid angle of capture |
up to 0.1 sr |
|
Focal spot size |
100-500 µm |
HOPG-based monochromators and focusing optics can be also used for neutron beams.
Specifications
|
Grade |
Mosaic spread |
Nominal thickness |
Minimum size |
Maximum size |
|
ZYH |
3.5+/-1.5 degrees |
2 (-1) mm |
10 mm x 10 mm |
50 mm x 50 mm |
Other sizes or specific mosaic spreads can be possible on request!