Nitrogen incorporation effects in Fe(001) thin films

Journal of Applied Physics

Tayal

Amir

et al. 2012

In this work we investigate the process of iron nitride (Fe-N) phase formation using 2 at.% Al or 2 at.% Ti as additives. The samples were prepared with a magnetron sputtering technique using different amount of nitrogen during the deposition process. The nitrogen partial pressure (\pn) was varied between 0-50% (rest Argon) and the targets of pure Fe, [Fe+Ti] and [Fe+Al] were sputtered. The addition of small amount of Ti or Al results in improved soft-magnetic properties when sputtered using \pn $\leq$ 10\p. When \pn is increased to 50\p non-magnetic Fe-N phases are formed. We found that iron mononitride (FeN) phases (N at% $\sim$50) are formed with Al or Ti addition at \pn =50% whereas in absence of such addition \eFeN phases (N\pat$\sim$30) are formed. It was found that the overall nitrogen content can be increased significantly with Al or Ti additions. On the basis of obtained result we propose a mechanism describing formation of Fe-N phases Al and Ti additives.Comment: 9 Pages, 7 Figure

Section: Introductionmentioning

confidence: 99%

Formation of iron nitride thin films with Al and Ti additives

Journal of Applied Physics

Tayal

Amir

et al. 2012

“…The adsorption and dissociation of gas phase molecules on various surfaces has been intensively studied [2,4,6,7,[11][12][13][14][15]. Dahl et al [12] studied the molecular dissociation of nitrogen on Ru(0001) surface and showed that it lowered the energy barrier for the molecular dissociation of nitrogen significantly.…”

Section: Introductionmentioning

confidence: 99%

$Ab$ $initio$ study of the adsorption and dissociation of nitrogen molecule on Fe(111) surface

Ryang,

Kim,

2014

Preprint

The adsorption and dissociation of nitrogen molecule on Fe(111) surface is studied by density functional theory calculations. The simulation results show that the molecule needs to acquire parallel orientation with respect to the surface for the adsorption and dissociation. In addition, Fe(111) surface is more active in dissociating N 2 than Fe(100) surface due to its morphology. The interaction between antibonding molecular orbitals of N 2 and partially filled 3d orbitals of Fe atoms on the surface may be the key to the molecular dissociation of N 2 . To break down the triple bond of N 2 , the electron density on the surface needs to be partially transferred to the molecule to fill the antibonding molecular orbitals of the nitrogen molecule. The present result may provide some insights on the dissociation mechanism of molecules over transition metal surfaces.

“…A proper understanding of the stability and nitride formation requires knowledge of both Fe and N self-diffusion at atomic length scales. Although the diffusion processes in magnetic bcc-iron nitrides have been discussed, 21,29,30 the diffusion coefficients for Fe and N selfdiffusion in nonmagnetic Fe-N have not been quantified. Conventional techniques for measuring self-diffusion (e.g., secondary ion mass spectroscopy, radioactive tracers, etc.)…”

Section: Introductionmentioning

confidence: 99%

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

Tayal²,

Journal of Applied Physics

et al. 2011

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