Synthesis and Characterization of the Nitrides of Platinum and Iridium
Jonathan C. Crowhurst,1*
Alexander F. Goncharov,1,2
Babak Sadigh,1
Cheryl L. Evans,1
Peter G. Morrall,1,3
James L. Ferreira,1
A. J. Nelson1
Transition metal nitrides are of great technological and fundamental
importance because of their strength and durability and because
of their useful optical, electronic, and magnetic properties.
We have evaluated a recently synthesized platinum nitride (PtN)
that was shown to have a large bulk modulus, and we propose
a structure that is isostructural with pyrite and has the stoichiometry
PtN
2. We have also synthesized a recoverable nitride of iridium
under nearly the same conditions of pressure and temperature
as PtN
2. Although it has the same stoichiometry, it exhibits
much lower structural symmetry. Preliminary results suggest
that the bulk modulus of this material is also very large.
1 Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94551, USA.
2 Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Road NW, Washington, DC 20015, USA.
3 AWE, Aldermaston, Reading, Berkshire RG7 4PR, UK.
These authors contributed equally to this work.
* To whom correspondence should be addressed. E-mail: crowhurst1{at}llnl.gov