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Structural and magnetic properties of Co-N thin films deposited using magnetron sputtering at 523 K

Pandey, Nidhi; Gupta, Mukul; Gupta, Rachana; Chakravarty, Sujay; Shukla, Neeraj and Devishvili, Anton (2017) In Journal of Alloys and Compounds 694. p.1209-1213
Abstract

In this work, we studied cobalt nitride (Co-N) thin films deposited using a dc magnetron sputtering method at a substrate temperature (Ts) of 523 K. We find that independent of the reactive gas flow (RN2 ) used during sputtering, the phases of Co-N formed at this temperature seems to be identical having N at.% ∼ 5. This is contrary to Co-N phases formed at lower Ts. For example at Ts∼ 300 K, an evolution of Co-N phases starting from Co(N) → Co4N → Co3 N → CoN can be seen as RN2 increases gradually to 100%, whereas when Ts increases to 523 K, the phase formed is fcc Co along with a minuscule Co4N phase for... (More)

In this work, we studied cobalt nitride (Co-N) thin films deposited using a dc magnetron sputtering method at a substrate temperature (Ts) of 523 K. We find that independent of the reactive gas flow (RN2 ) used during sputtering, the phases of Co-N formed at this temperature seems to be identical having N at.% ∼ 5. This is contrary to Co-N phases formed at lower Ts. For example at Ts∼ 300 K, an evolution of Co-N phases starting from Co(N) → Co4N → Co3 N → CoN can be seen as RN2 increases gradually to 100%, whereas when Ts increases to 523 K, the phase formed is fcc Co along with a minuscule Co4N phase for RN2 ≥ 25%. We used x-ray diffraction (XRD) to probe long range ordering, x-ray absorption spectroscopy (XAS) at Co absorption edge for the local structure, Magneto-optical Kerr effect (MOKE) and polarized neutron reflectivity (PNR) to measure the magnetization of samples. Quantification of N at.% was done using secondary ion mass spectroscopy (SIMS). Measurements suggest that the magnetic moment of Co-N samples deposited at 523 K is slightly higher than the bulk Co moment and does not get affected with the RN2 used for reactive sputtering. Our results provide an important insight about the phase formation of Co-N thin films which is discussed in this work.

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author
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Cobalt nitride thin films, Reactive nitrogen sputtering, Tetra cobalt nitride
in
Journal of Alloys and Compounds
volume
694
pages
5 pages
publisher
Elsevier
external identifiers
  • scopus:84992520608
ISSN
0925-8388
DOI
10.1016/j.jallcom.2016.10.095
language
English
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no
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fca9b57c-a5f6-4372-a40c-adcf2c3177a1
date added to LUP
2017-03-09 14:45:49
date last changed
2018-01-07 11:54:47
@article{fca9b57c-a5f6-4372-a40c-adcf2c3177a1,
  abstract     = {<p>In this work, we studied cobalt nitride (Co-N) thin films deposited using a dc magnetron sputtering method at a substrate temperature (T<sub>s</sub>) of 523 K. We find that independent of the reactive gas flow (R<sub>N<sub>2</sub> </sub>) used during sputtering, the phases of Co-N formed at this temperature seems to be identical having N at.% ∼ 5. This is contrary to Co-N phases formed at lower T<sub>s</sub>. For example at T<sub>s</sub>∼ 300 K, an evolution of Co-N phases starting from Co(N) → Co<sub>4</sub>N → Co<sub>3</sub> N → CoN can be seen as R<sub>N<sub>2</sub> </sub> increases gradually to 100%, whereas when T<sub>s</sub> increases to 523 K, the phase formed is fcc Co along with a minuscule Co<sub>4</sub>N phase for R<sub>N<sub>2</sub> </sub> ≥ 25%. We used x-ray diffraction (XRD) to probe long range ordering, x-ray absorption spectroscopy (XAS) at Co absorption edge for the local structure, Magneto-optical Kerr effect (MOKE) and polarized neutron reflectivity (PNR) to measure the magnetization of samples. Quantification of N at.% was done using secondary ion mass spectroscopy (SIMS). Measurements suggest that the magnetic moment of Co-N samples deposited at 523 K is slightly higher than the bulk Co moment and does not get affected with the R<sub>N<sub>2</sub> </sub> used for reactive sputtering. Our results provide an important insight about the phase formation of Co-N thin films which is discussed in this work.</p>},
  author       = {Pandey, Nidhi and Gupta, Mukul and Gupta, Rachana and Chakravarty, Sujay and Shukla, Neeraj and Devishvili, Anton},
  issn         = {0925-8388},
  keyword      = {Cobalt nitride thin films,Reactive nitrogen sputtering,Tetra cobalt nitride},
  language     = {eng},
  month        = {02},
  pages        = {1209--1213},
  publisher    = {Elsevier},
  series       = {Journal of Alloys and Compounds},
  title        = {Structural and magnetic properties of Co-N thin films deposited using magnetron sputtering at 523 K},
  url          = {http://dx.doi.org/10.1016/j.jallcom.2016.10.095},
  volume       = {694},
  year         = {2017},
}