Abstract
Fe4N thin films with (001) texture were prepared by reactive sputtering on MgO substrates, utilizing either a Cr or Ag buffer layer to facilitate the epitaxial growth. X-ray diffraction, atomic force microscopy, and vibrating sample magnetometry measurements show that the Fe4N thin film grown on the Ag buffer layer is superior to that grown on the Cr buffer layer. The point contact Andreev reflection measurement was then conducted, and the spin polarizations were determined to be 61.1% and 81.3% for Fe4N thin films with Cr and Ag buffer layers, respectively. The 81.3% spin polarization is significantly higher than the ratio reported previously for Fe4N and is comparable with that of state-of-the-art Heusler alloys. This result is in agreement with the theoretical prediction on the discrepancy between the two differently defined spin polarizations for Fe4N. Moreover, our study indicates that an optimized growth process for Fe4N thin films is crucial for achieving a high spin polarization and that true half-metallicity could potentially be realized with Fe4N. The high spin polarization of Fe4N combined with its low fabrication temperature and simple composition makes Fe4N a competitive candidate to be a half-metallic ferromagnet in spintronic devices.
| Original language | English (US) |
|---|---|
| Article number | 162407 |
| Journal | Applied Physics Letters |
| Volume | 112 |
| Issue number | 16 |
| DOIs | |
| State | Published - Apr 16 2018 |
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ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)
Cite this
High spin polarization in epitaxial Fe4N thin films using Cr and Ag as buffer layers. / Li, Hongshi; Li, Xuan; Kim, Dongrin; Zhao, Gejian; Zhang, Delin; Diao, Zhitao; Chen, Tingyong; Wang, Jian Ping.
In: Applied Physics Letters, Vol. 112, No. 16, 162407, 16.04.2018.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - High spin polarization in epitaxial Fe4N thin films using Cr and Ag as buffer layers
AU - Li, Hongshi
AU - Li, Xuan
AU - Kim, Dongrin
AU - Zhao, Gejian
AU - Zhang, Delin
AU - Diao, Zhitao
AU - Chen, Tingyong
AU - Wang, Jian Ping
PY - 2018/4/16
Y1 - 2018/4/16
N2 - Fe4N thin films with (001) texture were prepared by reactive sputtering on MgO substrates, utilizing either a Cr or Ag buffer layer to facilitate the epitaxial growth. X-ray diffraction, atomic force microscopy, and vibrating sample magnetometry measurements show that the Fe4N thin film grown on the Ag buffer layer is superior to that grown on the Cr buffer layer. The point contact Andreev reflection measurement was then conducted, and the spin polarizations were determined to be 61.1% and 81.3% for Fe4N thin films with Cr and Ag buffer layers, respectively. The 81.3% spin polarization is significantly higher than the ratio reported previously for Fe4N and is comparable with that of state-of-the-art Heusler alloys. This result is in agreement with the theoretical prediction on the discrepancy between the two differently defined spin polarizations for Fe4N. Moreover, our study indicates that an optimized growth process for Fe4N thin films is crucial for achieving a high spin polarization and that true half-metallicity could potentially be realized with Fe4N. The high spin polarization of Fe4N combined with its low fabrication temperature and simple composition makes Fe4N a competitive candidate to be a half-metallic ferromagnet in spintronic devices.
AB - Fe4N thin films with (001) texture were prepared by reactive sputtering on MgO substrates, utilizing either a Cr or Ag buffer layer to facilitate the epitaxial growth. X-ray diffraction, atomic force microscopy, and vibrating sample magnetometry measurements show that the Fe4N thin film grown on the Ag buffer layer is superior to that grown on the Cr buffer layer. The point contact Andreev reflection measurement was then conducted, and the spin polarizations were determined to be 61.1% and 81.3% for Fe4N thin films with Cr and Ag buffer layers, respectively. The 81.3% spin polarization is significantly higher than the ratio reported previously for Fe4N and is comparable with that of state-of-the-art Heusler alloys. This result is in agreement with the theoretical prediction on the discrepancy between the two differently defined spin polarizations for Fe4N. Moreover, our study indicates that an optimized growth process for Fe4N thin films is crucial for achieving a high spin polarization and that true half-metallicity could potentially be realized with Fe4N. The high spin polarization of Fe4N combined with its low fabrication temperature and simple composition makes Fe4N a competitive candidate to be a half-metallic ferromagnet in spintronic devices.
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U2 - 10.1063/1.5023698
DO - 10.1063/1.5023698
M3 - Article
AN - SCOPUS:85045836335
VL - 112
JO - Applied Physics Letters
JF - Applied Physics Letters
SN - 0003-6951
IS - 16
M1 - 162407
ER -