Size control of nanocrystalline magnetite thin films containing a small amount of Ge

作者：Abe Seishi^*; Ping De Hai; Usui Hiroyuki; Ohnuma Masato; Ohnuma Shigehiro

来源：Thin Solid Films, 2010, 518(20): 5690-5693.

DOI：10.1016/j.tsf.2010.04.070

• Transmission electron microscopy
• Sputtering
• Magnetite
• Germanium
• Transmittance
• X-ray diffraction
• Microstructure

This study investigated the preparation and particle size control of nanocrystalline magnetite (Fe(3)O(4)) containing a small amount of Ge. Thin films were prepared by radio-frequency sputtering with a composite target of Ge chips set on a Fe(3)O(4) compound target in a mixed atmosphere of Ar and O(2). X-ray diffraction revealed that the diffraction peak of magnetite gradually broadened as the oxygen ratio increased, with the mean grain size ranging from 26 to 2 nm. Transmission electron microscopy also revealed that the magnetite structurally changed from polycrystalline single phase to isolated granular nanocrystals. Magnetization at 8 x 10(5) A/m was monotonically reduced from 0.32 to 0.04T, and coercivity was monotonically reduced from 4.2 x 10(4) to 2.1 x 10(3) A/m with increasing the oxygen ratio from 0 to 0.4%.

• 出版日期2010-8-2