Formation of iron nitride thin films with Al and Ti additives

Abstract

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

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

“…Moreover, this barrier layer seems to have multiple effects as it not only suppresses Fe self-diffusion, it also hinders grain growth, leading to improved soft magnetic properties as observed in our samples with Al or Zr doping. The improvement in soft-magnetic properties of Fe-N thin films with dopants was also found in previous reports [34,77,78]. Somewhat superior thermal stability with Al doping can also be understood from the fact that only with Al doping N diffusion suppresses.…”

“…In attempts to make interstitial Fe-N more stable, addition or doping of impurity element(s) was proposed in such a way * mgupta@csr.res.in/dr.mukul.gupta@gmail.com that the amount of impurity must be low enough to affect the structural or the magnetic properties adversely [9,[21][22][23][24][25][26][27][28][29][30][31][32][33][34]. Such impurity doped systems were termed as Fe-X-N with X = few at.…”

DFT calculation and experimental investigation of Mn doping effect in Fe16N2

“…This observation confirms other published results. 3,19,22 However, the 10% Mn sample, with the help of the impurities in the sample, is stable even at 200…”

“…[22][23][24] However these works are mainly based on thin film samples for recording applications. Moreover, the choice of element is rather arbitrary and lacks any supporting theory.…”

“…The aspects of atomic size and affinity to N are always considered in other published works. [22][23][24] The ferromagnetic coupling situation with dopant has not yet been considered in terms of thermal stability. Here, the DFT calculation is used to include the coupling situation.…”