HOPG - highly oriented pyrolytic graphite

Applications

  •  Scanning tunneling microscopy-callibration and substrates
  •  Graphite Monochromators
  •  X-Ray diffraction
  •  Neutron scattering and diffraction

Physical Characteristics (at 300K)

 
Spacing of Reflecting Planes (002): 3.355 - 3.359 Å
Density: 2.255 - 2.265 gem-3
Thermal Conductivity
   Parallell (002):
   Perpendicular (002):

16 - 20 Watt/cm K
ca. 0.8 Watt/cm K
Thermal Expansion
   Parallell (002):
   Perpendicular (002):

Slightly negative
20 x 10-6 / K
Electrical Resistivity
   Parallell (002):
   Perpendicular (002):

3.5 - 4.5 x 10-5Ohm cm
0.15 - 0.25 Ohm cm

1) Mosaic spread is the half maximum height peak width of the Cu-Ka

Products

HOPG plates are produced as flat, singly-bent and double-bent shapes. The
monochromators are classified according to mosaic spread.

 

Grade Mosaic Spread Nominal thickness [mm]** Minimum* size [mm] Maximum* size [mm]
ZYA 0.4° ± 0.1° 2 12 x 12 50 x 50
ZYB 0.8° ± 0.2° 2 12 x 12 50 x 75
ZYD 1.2° ± 0.2° 2, 4 12 x 12 50 x 75
ZYH 3.5° ± 1.5° 2, 4, 6, 8 12 x 12 75 x 75

* other sizes or specific mosaic spread on request
** Tolerance ± 0/-1 mm

Standard radii for singly-bent plates: 115, 225, 250, 510, 790, and 1.300 mm.

Standard size for bent monochromators (mm):

12 x 12, 20, 25, 40 20 x 20, 25, 40, 50
15 x 15, 25, 40, 50 25 x 25, 40, 50, 75
 

Thickness for bent plates 2 + 0/-1 mm.

Other sizes and specifications on request