Iron and nitrogen self-diffusion in non-magnetic iron nitrides

Abstract

The self-diffusion of iron and nitrogen is measured in nm range non-magnetic iron nitride thin films. Two non-magnetic iron nitrides, Fe 2.23 N and FeN, were studied using neutron reflectivity. Neutron reflectivity with a depth resolution in the sub-nm range has a different scattering cross section for isotopes, providing a unique opportunity to measure very small diffusivities. The isotope heterostructure in thin film multilayers [Fe-N/ 57 Fe-N] 10 and [Fe-N/Fe-15 N] 10 were prepared using magnetron sputtering. It was observed that nitrogen diffuses slower than iron although the atomic size of iron is larger than that of nitrogen. It was found that a significantly larger group of N atoms participates in the diffusion process than of Fe, making N diffusion slower than that of Fe. V

Phase formation, thermal stability and magnetic moment of cobalt nitride thin films

“…performed. Using a procedure adopted for Fe-N thin films, 35,36 we find N at.% for R N 2 = 30 and 100% samples is 20 ± 3 and 50 ± 4, respectively, which is expected for Co 4 N and CoN structures. Grain sizes and a obtained from the most intense peak in XRD pattern are given in Table I.…”

Effect of dopants on thermal stability and self-diffusion in iron-nitride thin films

“…During the deposition, partial pressure in the chamber was about 4 × 10 −3 mbar. More details about the deposition system are given elsewhere [10,47] 57 Fe-Al-N(2 nm)] ×10 samples were deposited. All samples were deposited using identical deposition conditions.…”

“…It is known that these techniques are the only methods to probe self-diffusion in stable isotopes. While reflectivity techniques (PNR and NRR) offer an excellent depth resolution of about 0.1 nm [47,[59][60][61], the information obtained from these techniques is "indirect" as they are based on x-ray/neutron scattering. SIMS, on the other hand, provides depth profile of isotopes giving a "direct" information of diffusivity.…”

“…Since scattering length density (SLD) of neutrons is [43], B self-diffusion in amorphous boron [44], and N self-diffusion in Si 3 N 4 [45], Si-C-N [46], and iron monontrides (Nat. % ∼ 50) [47] compounds. Here it is worth noting that even with NR, measurement of N self-diffusion in interstitial Fe-N (N at.…”

“…From the decay in the intensity of Bragg peak selfdiffusivity in the samples can be calculated using the following expression [47,[59][60][61]:…”