The volume dependence of the magnetization and NMR of Fe₄N and Mn₄N

Abstract

The forced volume magnetostriction and the NMR of ferromagnetic FeN and ferrimagnetic Mn4N have been measured in the ordered state. At 4.2 K the magnetization ( sigma ) per unit mass and the effective field (HI) at the nucleus of the Fe(I) site of Fe4N are found to change with pressure such that delta ln sigma / delta P approximately= delta ln mod HI mod / delta P<0, while for Mn4N delta ln sigma / delta P approximately=6 delta ln mod HI mod / delta P>0. The result for Mn4N is interpreted as showing that the magnitude of the small (negative) moment on the Mn(II) site decreases more rapidly under pressure than does the large Mn(I) moment. The value of delta ln mod HI mod / delta P for Mn4N was found to be a strong function of temperature such that delta lnTN/ delta P approximately=5.2 Mbar-1. An analysis of the Mn4N NMR data suggests that the discrepancy between the calculated (spin) and measured moment at the Mn(I) site may be due to a small orbital moment at that site.

Structural stability and magnetism of γ′-Fe4N and CoFe3N compounds

“…The lattice parameter a is 3.598 Å. Due to the N insertion in the b site of ␥-Fe, the volume expansion is about 14.2%, which is smaller than the experimental value of Lord's [28].…”

The magnetization of γ′‐Fe4N: theory vs. experiment

“…Refs. [101] and [68] use NMR, the others use Mössbauer spectroscopy. The sign of B hf is usually not measured, but a negative sign is used throughout the table, as suggested by all available ab initio calculations (Table 6).…”

The effect of structure and phase transformation on the mechanical properties of Re2N and the stability of Mn2N

“…TcN was reported to be NaCl type. [20] As for manganese nitrides, ε-Mn 4 N, [21] ζ -Mn 2 N, [22] η-Mn 3 N 2 , [23][24][25] θ-Mn 6 N 5 , [23,24] and Mn 2 N 0.86 [26] were synthesized under pressures no more than 1 GPa and high temperatures ranging from 400 to 700…”