Synthesis of diamond with the highest nitrogen concentration

1
Synthesis of diamond with the highest nitrogen
concentration

• Introduction
• Nitrogen is the most common atomic impurity in
  diamond, and physical properties of diamond
  are influenced significantly by the form and
  concentration of this nitrogen.
• Concentrations and forms of Nitrogen, boron ??a,
  ?a, ?b, ?b
• ?a, ?b ? aggregated and isolated forms
• ?a ? the purest crystal
• ?b ? contains boron
• the most natural crystal ? ?a
• synthetic diamonds ? ?b

2

• It is easy to find natural diamonds containing
  more than 1000atppm of nitrogen.
• Diamond crystals with such a high concentration
  of nitrogen have not been synthesized in the
  laboratory.
• Typical synthetic diamonds contain a few
  hundred atppm of nitrogen.
• ?a ? up to 800ppm less than half of natural
  diamonds.
• (Even if nitrogen is doped in the growth cell,
  its concentration does not exceed that value.)
• Synthesis crystals are usually grown form
  conventional metal catalysts
• Non-metallic materials ( carbonates, hydroxides
  and sulfates)
• ? high a nitrogen concentration as
  natural crystals

3
(No Transcript)
4
(No Transcript)
5
(No Transcript)
6

• Summary
• High nitrogen concentrations as natural diamond
  were found to be incorporated into diamond grown
  form Na2SO4 in the laboratory.
• Nitrogen is incorporated easily by non-metallic
  catalysts because natural diamonds are inferred
  to grow from molten rocks. i.e., non-metallic
  catalysts.