Jump to main content
Jump to site search

Issue 20, 2010
Previous Article Next Article

High pressure synthesis of superconducting nitrides in the MoN–NbN system

Author affiliations


We have synthesized a range of Mo–Nb nitrides at 2.5 GPa and T = 1600 °C or 2200 °C using high pressure–high temperature techniques. Following syntheses at 1600 °C Mo-rich compositions are hexagonal and Nb-rich phases are cubic, with a narrow two-phase region indicating the presence of a solvus. The maximum Mo content in the cubic phase derived from δ-NbN is 40–44 mol%, and the maximum Nb content in the hexagonal δ-MoN phase is 46–47 mol%. There was little variation in the superconducting transition temperature Tc for hexagonal δ-(Mo,Nb)N samples produced in the study. Previous studies showed maximum Tc values of 12–15 K for pure δ-MoN as a function of N-site ordering in high-P,T experiments. Here we recorded Tc = 14 K for the limiting Mo-rich composition prepared in the study. We observed Tc = 11.5–16 K for cubic δ-NbN depending on high-P,T synthesis and annealing conditions. This value falls to 5 K for the cubic Mo0.37Nb0.63N0.98 solid solution phase. Some high-P,T synthesis or annealing experiments were carried out at T = 2200 °C. At this temperature δ-MoN decomposes to produce γ-MoN0.54. A minor phase in this sample achieves Tc = 9.5 K. A new superconducting hexagonal oxynitride MoN0.74O0.38 with Tc = 16 K was also produced during this study.

Graphical abstract: High pressure synthesis of superconducting nitrides in the MoN–NbN system

Back to tab navigation

Article information

14 Oct 2009
11 Mar 2010
First published
01 Apr 2010

J. Mater. Chem., 2010,20, 4176-4182
Article type

High pressure synthesis of superconducting nitrides in the MoNNbN system

E. Bailey and P. F. McMillan, J. Mater. Chem., 2010, 20, 4176
DOI: 10.1039/B920468G

Search articles by author