Description
Calcium nitride has the formula of Ca3N2 and the
molecular weight of grams per mole. It can be prepared
by the reactionofCametal inapure streamof nitrogen gas:
3Ca + 2N2 ? Ca3N2
A second method is the decomposition of an amide:
3Ca(NH2)2 + heat ? Ca3N2 + 4NH3
This must be accomplished in an inert atmosphere
(not nitrogen gas). It is a reddish-brown powder. Its
CAS number is 12013-82-0 and its density is 2.76 g/
cm
3. It melts at 1195 °C (2183 F).α-Calcium nitride
is the commonly encountered form. It has an antibixbyite
structure similar to Mn2O3, except that the
positions of the ions are reversed: calcium (Ca
2+)
ions take the oxide (O
2-) positions and nitride ions
(N
3-) that of the manganese (Mn
3+). If Ca metal is
burned in air, it forms the oxide, CaO, and the
nitride, Ca3N2. The latter reacts with atmospheric
moisture to produce the hydroxide of calcium and
ammonia:
Ca3N2 + 6H2O ? 3Ca(OH)2 + 2NH3
Chemical Properties
12mm pieces and smaller, -200 mesh 99% pure; brown crystal(s); hex: a=0.3533nm, c=0.411 nm; cub: a=1.138 nm [CIC73] [CER91]
Uses
Recent advances in the utilization of single crystals for
a wide variety of purposes, especially in various electronic
surveillance and detection applications, has generated
considerable research in the development of improved
techniques for growing single crystalline materials. A
problem has arisen, however, in that many of the methods
relied upon heretofore fail to growcrystals having a reproducibly
high quality. Calcium nitride as a high temperature
solvent has been used in the recrystallization of
refractory aluminum nitride, that is growing single crystals
of aluminum nitride from a molten solution containing
the refractory material as the solute, and calcium
nitride as the solvent. Crystallization is accomplished by
the precipitation or crystallization of the solute, the solute
being the desired crystal, from the molten solution.
