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Co-ferrite thin film with spinel structure is attractive for spintronics and multifunctional devices. So far, single-crystal substrates are necessary to introduce perpendicular magnetic anisotropy in co-ferrite films. In this paper, a unique process has been developed to deposit co-ferrite thin films onto thermally oxidized silicon wafer with perpendicular magnetic anisotropy. We have successfully prepared co-ferrite films with (00l) orientation. Those films show perpendicular coercivities as large as 12.8 kOe. X-ray diffractometry results revealed that compressive strain, which is introduced by the postannealing process rather than deposition process, is as large as 1.3% in films with (00l) orientation. The large coercivity and perpendicular magnetic anisotropy can be quantitatively explained by the magnetoelastic effect. This silicon-compatible fabrication process is useful to further extending the applications of co-ferrite films. [ABSTRACT FROM AUTHOR]

Substituted strontium ferrite (\SrFe12-x{(\Cr0.5\Al0.5)}_x\O19) thin films were formed along the surface of multiwalled carbon nanotubes (MWCNTs). Mössbauer spectroscopy indicates that the substituted cations preferentially occupy the 12k sites. X-ray diffraction (XRD), transmission electron microscope (TEM), field emission scanning electron microscope (FE-SEM), vibrating sample magnetometer (VSM), and vector network analyzer were used to analyze the structure, static, and high-frequency magnetic properties of the prepared samples. It was found that with an increase in substitution content, the saturation of magnetization decreases while the coercivity increases. The CNTs could enhance the real and imaginary parts of permittivity of ferrites. With an increase in volume percentage of MWCNTs, the reflection loss values were increased. [ABSTRACT FROM AUTHOR]

Abstract: Pt, Pd, and Pt–Pd alloy underlayers were used to deposit c-axis oriented barium ferrite (BaM) thin films by a facing target sputtering system. All of the BaM thin films grown on these three underlayers show c-axis orientation normal to the film plane. But the grain size of BaM layer is strongly manipulated by the underlayer grain size. It is found that Pt–Pd alloy underlayer is effective to achieve c-axis oriented barium ferrite films with small grain size. [Copyright &y& Elsevier]

Abstract: Strontium ferrite (SrM) thin films were deposited on thermally oxidized silicon wafer with Au underlayer. Gold underlayers were prepared at various substrate temperatures by using a magnetron sputtering system. C-axis oriented SrM perpendicular films and preferred (111) orientation of underlayer have confirmed by X-ray diffraction patterns. The intensity of (111) diffraction line for Au and that of (00 l) diffraction line for strontium ferrite decrease with increase in substrate temperature (T u) The maximum coercivity and remanent squareness ratio in perpendicular direction, at T u of 500°C, are 5.4kOe and 0.68, respectively. The strength of the intergranular interaction of SrM magnetic particles is described by the parameter Δm. The SrM/Au films prepared at T u above 100°C have smaller Δm peak values than that for SrM/Au films prepared at T u of room temperature. This behavior is related to low magnetostatic coupling between the magnetic particles separated by the non-magnetic amorphous phase. [Copyright &y& Elsevier]