You can buy Highly Oriented Pyrolytic Graphite (HOPG) sheets from PAM-XIAMEN. HOPG is a relatively new form of high purity carbon and provides microscopists with a renewable and smooth surface. Unlike mica, HOPG is completely non-polar, and for samples where elemental analysis will also be done, it provides a background with only carbon in the elemental signature. The extreme smoothness of HOPG gives results in a featureless background, except at atomic levels of resolution.
1. Specifications of HOPG Film
|Item||HOPG Substrate (PAM210713-GRAPHITE)||Remark|
|Diameter||25.4 mm x 2 mm|
|Thermal expansion coefficient||3.2 x 10-6 /℃||(a b)|
|Thermal conductivity||0.9 K/cm.s. ℃ |
5 x 10-3 K/cm.s. ℃
|(a b), close to copper |
(c), equivalent to ceramic material
|Electrical resistance||2 x 10-4 ohm/cm |
|(a b) |
|Flexural strength||120 MPa||(a b)|
|Tensile strength||>/= 75 MPa||(a b)|
|Compressive strength||>/= 83.60 MPa||(a b)|
|Airtight||Helium permeability <10-10 cm2|
Highly Oriented Pyrolytic Graphite Sheet (SPI-2 Grade), 5x5X1.0 mm, As Cleaved
Highly Oriented Pyrolytic Graphite Substrate (SPI-2 Grade), 10x10X1.0 mm, As Cleaved
Highly Oriented Pyrolytic Graphite Wafer (SPI-2 Grade), 20x20X2.0 mm, As Cleaved
Highly Oriented Pyrolytic Graphite Film (SPI-1 Grade), 10x10X1.0 mm, As Cleaved
2. Highly Oriented Pyrolytic Graphite Basal Plane Properties
The volume elastic properties of HOPG are similar to those of natural graphite single crystal phase, and the room temperature shear strength of its parallel layer direction is 0.9~2.5MPa.
The physical properties of HOPG are very close to single crystal graphite.
X-ray Diffraction Properties of Highly Oriented Pyrolytic Graphite
3. Growth of Highly Oriented Pyrolytic Graphite
HOPG is a kind of “crystalline” graphite with good crystal structure, strong preferential orientation and high degree of graphitization. The preparation principle is to use fine-cone structure pyrolytic graphite (PG) as the basic raw material. After multiple special process treatments, and then use high-temperature hot-pressing equipment to produce after high-temperature and high-pressure treatment. Under the high temperature and high pressure state, the grain structure of PG quickly transforms, the arrangement of carbon atoms becomes more orderly, and the original “chaotic stacking” structure is transformed into a very strong grain orientation. The arrangement form of a “quasi-crystal” turns to a highly ordered pyrolytic graphite, which is similar to the ideal pyrolytic graphite structure.
4. HOPG Application
Due to its good carbon atom structure, HOPG has been widely used as standard samples and key components in scientific research, instrument manufacturing, and industrial production. At present, its main applications include basic performance research of X-ray monochromator, neutron filter & monochromator and graphite and basic research of large-size graphite interlayer compounds, etc.