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Title: Magnetic and physical microstructure of Fe{sub 16}N{sub 2} films grown epitaxially on Si(001)

Abstract

Epitaxial Fe{sub 16}N{sub 2} films were grown on Si(001) substrates with an Ag underlayer by reactive sputtering in nitrogen. Pure {alpha}{sup {prime}}-Fe{sub 8}N films were obtained which on subsequent annealing resulted in mixtures of {alpha}{sup {prime}}-Fe{sub 8}N (54{percent}) and {alpha}{sup {prime}{prime}}-Fe{sub 16}N{sub 2} (46{percent}). An average moment of 1780 emu/cc, considerably larger than that of pure {alpha}-Fe (1714 emu/cc), was measured for both samples. Plan-view transmission electron microscopy of the films confirms the orientation relationship Fe{sub 16}N{sub 2}(001){parallel}Ag(001){parallel}Si(001) and Fe{sub 16}N{sub 2}[100]{parallel}Ag[110]{parallel}Si[100], and a small grain size ({approximately}100 {Angstrom}), while electron energy-loss spectroscopy confirms an average composition of Fe{sub 8}N for both samples. Electron diffraction patterns indicate that the as-deposited {alpha}{sup {prime}} films already contain very small regions of ordered {alpha}{sup {prime}{prime}} which were not previously detected by x-ray diffraction measurements. M{umlt o}ssbauer spectroscopy performed at both 300 and 16 K gave three hyperfine fields corresponding to three different iron sites for both the unannealed {alpha}{sup {prime}} and the annealed {alpha}{sup {prime}}/{alpha}{sup {prime}{prime}} mixtures. Lorentzian fitting of the three iron components for the {alpha}{sup {prime}}/{alpha}{sup {prime}{prime}} spectrum obtained at room temperature gave an intensity ratio of 1:2:1 (FeI:FeII:FeIII) corresponding to the expected occupancy for the three Fe sites in themore » Fe{sub 16}N{sub 2} structure. Moreover, the pure {alpha}{sup {prime}} film at 300 K and both samples at 16 K showed deviation from this distribution. The three components show notable differences in the temperature dependence of their occupancies; however, all three magnetic components deviate similarly from the surface normal. {copyright} {ital 1997 American Institute of Physics.}« less

Authors:
; ;  [1]; ;  [2]
  1. Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
  2. Department of Physics, Shiga University of Medical Science, Seta, Otsu, 520-21 Shiga (Japan)
Publication Date:
OSTI Identifier:
496433
Report Number(s):
CONF-961141-
Journal ID: JAPIAU; ISSN 0021-8979; TRN: 97:016134
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 81; Journal Issue: 8; Conference: 41. annual conference on magnetism and magnetic materials, Atlanta, GA (United States), 12-15 Nov 1996; Other Information: PBD: Apr 1997
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 66 PHYSICS; IRON NITRIDES; MAGNETIC MOMENTS; IRON COMPOUNDS; ANNEALING; TRANSMISSION ELECTRON MICROSCOPY; GRAIN SIZE; MICROSTRUCTURE; THIN FILMS; EPITAXY; SPUTTERING; MOESSBAUER EFFECT; ELECTRON DIFFRACTION; X-RAY DIFFRACTION

Citation Formats

Brewer, M A, Echer, C J, Krishnan, K M, Kobayashi, T, and Nakanishi, A. Magnetic and physical microstructure of Fe{sub 16}N{sub 2} films grown epitaxially on Si(001). United States: N. p., 1997. Web. doi:10.1063/1.365102.
Brewer, M A, Echer, C J, Krishnan, K M, Kobayashi, T, & Nakanishi, A. Magnetic and physical microstructure of Fe{sub 16}N{sub 2} films grown epitaxially on Si(001). United States. https://doi.org/10.1063/1.365102
Brewer, M A, Echer, C J, Krishnan, K M, Kobayashi, T, and Nakanishi, A. Tue . "Magnetic and physical microstructure of Fe{sub 16}N{sub 2} films grown epitaxially on Si(001)". United States. https://doi.org/10.1063/1.365102.
@article{osti_496433,
title = {Magnetic and physical microstructure of Fe{sub 16}N{sub 2} films grown epitaxially on Si(001)},
author = {Brewer, M A and Echer, C J and Krishnan, K M and Kobayashi, T and Nakanishi, A},
abstractNote = {Epitaxial Fe{sub 16}N{sub 2} films were grown on Si(001) substrates with an Ag underlayer by reactive sputtering in nitrogen. Pure {alpha}{sup {prime}}-Fe{sub 8}N films were obtained which on subsequent annealing resulted in mixtures of {alpha}{sup {prime}}-Fe{sub 8}N (54{percent}) and {alpha}{sup {prime}{prime}}-Fe{sub 16}N{sub 2} (46{percent}). An average moment of 1780 emu/cc, considerably larger than that of pure {alpha}-Fe (1714 emu/cc), was measured for both samples. Plan-view transmission electron microscopy of the films confirms the orientation relationship Fe{sub 16}N{sub 2}(001){parallel}Ag(001){parallel}Si(001) and Fe{sub 16}N{sub 2}[100]{parallel}Ag[110]{parallel}Si[100], and a small grain size ({approximately}100 {Angstrom}), while electron energy-loss spectroscopy confirms an average composition of Fe{sub 8}N for both samples. Electron diffraction patterns indicate that the as-deposited {alpha}{sup {prime}} films already contain very small regions of ordered {alpha}{sup {prime}{prime}} which were not previously detected by x-ray diffraction measurements. M{umlt o}ssbauer spectroscopy performed at both 300 and 16 K gave three hyperfine fields corresponding to three different iron sites for both the unannealed {alpha}{sup {prime}} and the annealed {alpha}{sup {prime}}/{alpha}{sup {prime}{prime}} mixtures. Lorentzian fitting of the three iron components for the {alpha}{sup {prime}}/{alpha}{sup {prime}{prime}} spectrum obtained at room temperature gave an intensity ratio of 1:2:1 (FeI:FeII:FeIII) corresponding to the expected occupancy for the three Fe sites in the Fe{sub 16}N{sub 2} structure. Moreover, the pure {alpha}{sup {prime}} film at 300 K and both samples at 16 K showed deviation from this distribution. The three components show notable differences in the temperature dependence of their occupancies; however, all three magnetic components deviate similarly from the surface normal. {copyright} {ital 1997 American Institute of Physics.}},
doi = {10.1063/1.365102},
url = {https://www.osti.gov/biblio/496433}, journal = {Journal of Applied Physics},
number = 8,
volume = 81,
place = {United States},
year = {1997},
month = {4}
}