Nitrogen concentration driving the hardness of rhenium nitrides.
The structures and properties of rhenium nitrides are studied with density function based first principle method. New candidate ground states or high-pressure phases at Re:N ratios of 3:2, 1:3, and 1:4 are identified via a series of evolutionary structure searches. We find that the 3D polyhedral stacking with strong covalent N-N and Re-N bonding could stabilize Re nitrides to form nitrogen rich phases, meanwhile, remarkably improve the mechanical performance than that of sub-nitrides, as Re3N, Re2N, and Re3N2. By evaluating the trends of the crystal configuration, electronic structure, elastic properties, and hardness as a function of the N concentration, we proves that the N content is the key factor affecting the metallicity and hardness of Re nitrides.
State Key Laboratory of Superhard Materials, College of physics, Jilin University, Changchun, 130012, P. R. China.
Zhonglong
Z
Zhao
State Key Laboratory of Superhard Materials, College of physics, Jilin University, Changchun, 130012, P. R. China.
Kuo
K
Bao
State Key Laboratory of Superhard Materials, College of physics, Jilin University, Changchun, 130012, P. R. China.
Da
D
Li
State Key Laboratory of Superhard Materials, College of physics, Jilin University, Changchun, 130012, P. R. China.
Defang
D
Duan
State Key Laboratory of Superhard Materials, College of physics, Jilin University, Changchun, 130012, P. R. China.
Fubo
F
Tian
State Key Laboratory of Superhard Materials, College of physics, Jilin University, Changchun, 130012, P. R. China.
Xilian
X
Jin
State Key Laboratory of Superhard Materials, College of physics, Jilin University, Changchun, 130012, P. R. China.
Changbo
C
Chen
State Key Laboratory of Superhard Materials, College of physics, Jilin University, Changchun, 130012, P. R. China.
Xiaoli
X
Huang
State Key Laboratory of Superhard Materials, College of physics, Jilin University, Changchun, 130012, P. R. China.
Bingbing
B
Liu
State Key Laboratory of Superhard Materials, College of physics, Jilin University, Changchun, 130012, P. R. China.
Tian
T
Cui