Structural and magnetic properties of NiCxand NiNx(x=0to

Chung Fang

¹

,

Marcel H. F. Sluiter

²

,

Marijn A. van Huis

³

et al.

Abstract

First-principles calculations have been performed for a variety of Ni 3 X (X = C, N) phases, as well as for NiX y (y = 0 to 1 3 ) solid solutions to clarify the persistent controversy regarding its magnetic state. The calculations show that the solid solution phases based on hexagonal-close-packed (hcp or ε-) Ni have relatively high stability for X concentrations greater than about 0.1 whereas the face-centered-cubic (fcc or γ -) Ni phases are favored for smaller X concentration. Hence, during carburization or nitridization of Ni, a phase transformation is to be expected. In spite of the close-packed nature of both hcp-and fcc-based solid solutions, X quenches the magnetization more effectively in fcc than in hcp-based solid solutions. These findings resolve many apparently contradictory experimental observations concerning C-and N-containing Ni alloys in the literature.

Predicted stability, structures, and magnetism of 3d transition metal nitrides: the M4N phases

“…While I-M 4 N is magnetic, chemical changes II-Ni 4 N 1AEx (with x $ 0.03) cause local distortion and the defective phases becomes non-magnetic. 41 That is also the case for II-Ni 4 N.…”

“…The formation energy (DE) of a metal nitride with the formula, M 4 N, M ¼ Sc to Cu with respect to the elemental 3d transition metal M and the N 2 molecule can be described as: 41,54,55 …”

“…6,[36][37][38][39][40] In the rst-principles' study of stability and electronic and magnetic properties of nickel nitrides, Fang and co-workers revealed that I-Ni 4 N is magnetic while I-Ni 4 N 1AEx (x $ 0.1) phases are non-magnetic due to the distortion of the FCC Ni sub-lattice caused by extra/deciency of N atoms. 41 More theoretical studies were conducted on the electronic and magnetic properties of ternary I-(A x M 1Àx ) 4 N phases where A is a metallic element and M a 3d transition metal.…”

“…47 Up to now, theoretical calculations have been performed mainly for I-M 4 N with M ¼ Mn, Fe, Co, Ni and Cu, [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41]48,49 and there is lack of knowledge about the formation and stability, and physical properties of the II-M 4 N phases.…”

First principles study on the structural, electronic and magnetic properties of Ni4C

“…But studies on NieC system are quite limited. Fang and Sluiter have studied the structural and magnetic properties of Ni 3 C phases and hcp-NiC y solid solution using first-principles calculations [11] and the results showed that the nonmagnetic solution was the most stable for both hcp-Ni 3 N and 3ReNi 3 C, and the hcp-NiX y solid solutions remained ferromagnetic up to y~0. 20.…”