Fabrication of ordered Fe–Ni nitride film with equiatomic Fe/Ni ratio

Abstract

We successfully grew a single-phase tetragonal FeNiN film with an equiatomic ratio of Fe, Ni, and N on a MgO(001) substrate by molecular beam epitaxy. We then demonstrated the formation of Fe 2 Ni 2 N films by extracting N atoms from the FeNiN film. These results suggested that Fe and Ni atoms in the Fe 2 Ni 2 N film were L1 0 -ordered along the film plane direction because of the a-axis orientation growth of the FeNiN film on the MgO(001) substrate.

Density Functional Theory description of the order-disorder transformation in Fe-Ni

“…Recently, interest in L1 0 FeNi has intensified after researchers invented a new and practicable technique to form tetragonal FeNi with a high degree of order. This new technique works through nitrogen insertion and topotactic extraction 7,8 .…”

Metal‐Rich Ternary Perovskite Nitrides

“…[98] For thin films with overall composition of Fe 2 Ni 2 N and thickness in the order of 40 nm fabricated by molecular beam epitaxy an observed tetragonal distortion of the cubic structure may suggest order within layers parallel to (100). [104] Fe 4-x Mn x N bulk samples were obtained with x up to 1. [105] Mößbauer spectroscopy indicated random arrangement of iron and manganese over both sites, possibly with little preference of Mn for the site distant to N, which was associated with the similar radii of both metals in agreement with an only slightly larger cubic unit cell of the binary manganese nitride as compared to γ′-Fe 4 N. Improvement of magnetic properties, particularly the remanence and the coercive field with manganese substitution was discussed as advantageous for magnetic recording.…”

“…Highly (100) orientated Fe 3 NiN thin films on sapphire substrate presented ferromagnetic with square‐shaped hysteresis and were proposed for spintronic devices and magnetic sensors . For thin films with overall composition of Fe 2 Ni 2 N and thickness in the order of 40 nm fabricated by molecular beam epitaxy an observed tetragonal distortion of the cubic structure may suggest order within layers parallel to (100) …”

Fabrication of <i>L</i>1₀-FeNi films by denitriding FeNiN films

“…13 ultra-high vacuum chamber supplying Fe, Ni, and radio-frequency (RF) N2 plasma, simultaneously. 15) The lattice mismatches in the c plane between FeNiN and the substrates are 2.5 (STO), 0.98 (MAO), and 4.9 % (MgO). Supply rates of Fe and Ni were controlled to get the equiatomic composition of Fe and Ni.…”

“…This is attributed to the long-range order of N atoms in the FeNiN films. 15) Figures 4(a) and 4(b) show the XRR patterns of the sample grown on the STO(001) substrate before and after the denitriding process, respectively. The red and blue curves correspond to the experiments and the calculations based on the models shown in the right-hand figures, respectively.…”