Hiroaki Chihaya

Enhancement in layer-by-layer growth in heteroepitaxial growth of Co on Au(111) surface by Bi surfactant

The surfactant effect of Bi on the heteroepitaxial growth of Co on the Au(111) surface has been studied. With the predeposition of submonolayer Bi on Au(111) prior to evaporation of Co, more long-lasting reflection high-energy electron diffraction intensity oscillations were observed at room temperature. This implied that Bi enhanced the layer-by-layer growth of Co on the Au(111) surface. The dependence of the Co film growth on the thickness of the Bi surfactant layer suggested that there existed a suitable amount of Bi surfactant that enhanced a smoother layer-by-layer growth. The Auger electron spectra revealed that Bi was segregated at the top of the surface. Therefore, Bi was concluded to be an effective surfactant to enhance the layer-by-layer growth of Co on Au(111).

EFFECT OF Bi SURFACTANT IN THE HETEROEPITAXIAL GROWTH OF Co ON Cu SURFACES

We have investigated the effect of Bi on the heteroepitaxial growth of Co on Cu by reflection high-energy electron diffraction (RHEED) measurements. It was found that Bi enhanced the layer-by-layer growth of Co on the Cu(111) surfaces at 100°C. The dependence of the growth on Bi layer thickness suggested that there existed a suitable amount of Bi surfactant layer that enhanced smoother layered growth. On the contrary, for the case of Co growth on Cu(100), Bi depressed the layer-by-layer growth of Co on Cu(100). The surface segregation effect of Bi was also studied by Auger electron spectroscopy (AES).

Bi-enhanced Heteroepitaxial Layered Growth of Cr on Fe(100)-c(2× 2)O Reconstruction Surfaces

We have investigated the effect of Bi on the homoepitaxial growth of Cr on Fe(100) by reflection high-energy electron diffraction (RHEED) measurements. It was found that Bi enhances the layered growth of Cr on Fe(100)-c(2× 2)O reconstruction surfaces. The dependence of the growth on Bi layer thickness suggests that there exists a suitable amount of Bi surfactant layer that enhances smoother layered growth. The surface segregation effect of Bi was studied by Auger electron spectroscopy.

Effects of interlayer exchange coupling on transport properties of Co∕Pd metallic multilayers with perpendicular magnetic anisotropy

Ru-mediated interlayer exchange coupling (IEC) was introduced in Co∕Pd(111) metallic multilayers with perpendicular magnetic anisotropy. The magnetic and electronic transport properties were investigated. The magnetically controlled Co∕Pd(111) multilayers exhibited unique resistivity changes. This is quite common in perpendicular antiferromagnetically (AF) coupled systems where the AF coupled multilayer stacks switch separately during field reversal. However, we found that even within the stacks, the individual ferromagnetic layers switch separately, such that the AF configurations are present during reversal even within the same multilayer stack. On considering the magnetic reversal and transport properties of the Co∕Pd multilayers, the IEC was found to cause antiferromagnetic alignment inside a multilayer stack that was sandwiched between two Ru layers. This phenomenon is mainly due to the thicker Pd films between the Co layers that allow more decoupling of individual Co layers than those employed in mo...