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The perpendicular magnetic properties of CoCr films on GaAs substrates are investigated by magneto-optical Kerr-effect measurements. The direct deposition of the CoCr film on the GaAs substrate did not show any perpendicular properties and the thickness dependence of the hysteresis loop and the magnetic force microscopy showed that the onset thickness of ferromagnetism was 6.5nm.

Epitaxial multilayers were studied to determine strain-induced magnetic anisotropy.

A new study investigates the Schottky barrier height of MnSb(001)/GaAs(111)B diodes.

The epitaxial growth of zinc-blende CrAs/GaAs multilayer with thick zinc blende-CrAs layer in total is examined. CrAs and GaAs do not grown epitaxially when the thickness of CrAs layer is greater than 2 ML and the thickness of GaAs layer is smaller than 2 ML.

We investigated the dependence of the performance of magnetic force microscopy (MFM) on magnetic coating materials by using carbon nanotube (CNT) probes. The magnetic structures of CNT-MFM probes with CoFe(80:20), CoFe(30:70), and CoCr(80:20) coatings were essentially the same in the simulations, but their magnetic properties, such as stability after magnetic reversal, varied slightly in the experiments. It was found that a larger saturation magnetic moment (Ms) is of advantage for attaining high spatial resolution. Although the distinction was hard to see in the MFM images, the experiments and simulations showed that CNT probes coated with high Ms materials gave stronger perturbations to soft magnetic materials than probes coated with low Ms materials. [ABSTRACT FROM AUTHOR]

Spin-dependent transport of the photoexcited electrons in the semiconductor (p-GaAs)/insulator (Al[sub 2]O[sub 3])/ferromagnetic metal (permalloy) junctions was investigated. As samples, homogeneous tunneling junctions were prepared on the flat and As-defect-free GaAs(111)B homoepitaxial surface by in situ oxidation of the Al layer and successive metallization by permalloy deposition. Spin-polarized electrons were excited in the GaAs by circularly polarized light and injected into the permalloy layer. Since the permalloy has almost zero magnetic circular dichroism at the vicinity of the band gap energy of GaAs, we can detect spin-dependent current exclusively. As a result, the energy dependence of the observed helicity asymmetry (1.44-3.05 eV) of the photoinduced current shows the absence of the spin-dependent tunneling in the sample. The importance of controlling the electron lifetime to obtain the spin-dependent tunneling was discussed. [ABSTRACT FROM AUTHOR]

Epitaxial multilayers of Fe[sub 3]O[sub 4]/Co[sub 3]O[sub 4] were successfully grown on MgO and SrTiO[sub 3](001) single crystal substrates using a molecular beam epitaxy apparatus. The multilayers showed a strong in-plane magnetic anisotropy and an increase of coercive field for thin Fe[sub 3]O[sub 4] samples. Multilayered Co[sub 3]O[sub 4] exhibited a significant lattice expansion along the growth direction in order to compensate lattice mismatch at the interface. A small lattice distortion in the Fe[sub 3]O[sub 4] layers might be the origin of the strong anisotropy. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]