Anomalous magnetic properties of an iron film system deposited on fracture surfaces of $\alpha$-Al2O3 ceramics
Jiao Zhi-Wei(焦志伟)a)b), Chen Miao-Gen(陈苗根)b), Jiang Wei-Di(姜伟棣)b), Feng Chun-Mu(冯春木)c), and Ye Gao-Xiang(叶高翔)a)†
aDepartment of Physics, Zhejiang University, Hangzhou 310027, China; bDepartment of Physics, China Jiliang University, Hangzhou 310018, China; c Test and Analysis Center, Zhejiang University, Hangzhou 310028, China
Abstract An iron film percolation system is fabricated by vapour-phase deposition on fracture surfaces of $\alpha$-Al2O3 ceramics. The zero-field-cooled (ZFC) and field-cooled (FC) magnetization measurement reveals that the magnetic phase of the film samples evolve from a high-temperature ferromagnetic state to a low-temperature spin-glass-like state, which is also demonstrated by the temperature-dependent ac susceptibility of the iron films. The temperature dependence of the exchange bias field $H_{\rm e}$ of the iron film exhibits a minimum peak around the temperature $T$=5 K, which is independent of the magnitude of the cooling field $H_{\rm cf}$. However, for $T > 10$ K, (1) $H_{\rm e}$ is always negative when $H_{\rm cf}$=2 kOe and (2) for $H_{\rm cf }$= 20 kOe (1Oe$\approx$80 A/m), $H_{\rm e}$ changes from negative to positive values as T increases. Our experimental results show that the anomalous hysteresis properties mainly result from the oxide surfaces of the films with spin-glass-like phase.
Received: 07 November 2007
Revised: 18 May 2008
Accepted manuscript online:
PACS:
75.70.Ak
(Magnetic properties of monolayers and thin films)
Fund: Project supported by the National
Natural Science Foundation of China (Grant Nos 10574109 and
50701037) and the Zhejiang Provincial Science
and Technology Department of China (Grant No 2005C24008).
Cite this article:
Jiao Zhi-Wei(焦志伟), Chen Miao-Gen(陈苗根), Jiang Wei-Di(姜伟棣), Feng Chun-Mu(冯春木), and Ye Gao-Xiang(叶高翔) Anomalous magnetic properties of an iron film system deposited on fracture surfaces of $\alpha$-Al2O3 ceramics 2008 Chin. Phys. B 17 3499
Altmetric calculates a score based on the online attention an article receives. Each coloured thread in the circle represents a different type of online attention. The number in the centre is the Altmetric score. Social media and mainstream news media are the main sources that calculate the score. Reference managers such as Mendeley are also tracked but do not contribute to the score. Older articles often score higher because they have had more time to get noticed. To account for this, Altmetric has included the context data for other articles of a similar age.
