Faculty
Kiyoshi Sakaue
Major research fields
Solid State Physics, Crystal Growth
I am interested in materials with artificial structure, such as so-called multilayers or Suberlattices, and in their physical properties. Metallic multilayers have the alternate stacking of thin films with two or more different metals grown on the substrate (structural modulation). Usually, the multilayers are in a poly-crystalline state, but when they are of ahighly ordered state like single crystals, we call them 'Superlattices'. We are great interested in the remarkable physical properties originating from structural modulation.
For example, giant magneto-resistance (GMR) is one of the better-known features, which is applied to the magnetic sensors for hard disk drives. The aim of our research of multilayes is to clarify the relationship between the physical properties and the structural parameters of the multilayers, that is, to find the answer to the question "Why do multilayers shows such particular physical properties?" In my laboratory, multilayers are synthesized with a substrate being exposed to the metal vapor which is made by heating the solid source with temperature of about one or two thousand Kelvin in high vaccum. We characterize the surface and bulk sturcture of the thin multilayers (i.e. thickness of each layer, modulation length, surface and interface roughness, crystallinity and lattice distortion of the multilayer) using X-ray reflectivity, wide-angle X-ray diffraction and the atomic force microscopy (AFM). We also measure the physical properties (i.e. transport properties such as electric reistivity, heat conductance, mechanical properties) using a variety of methods.
Major relevant publications
- Tamura,K., Miyaguchi,S., Sakaue,K., Nishihata,Y., and Mizuki,J., ;Direct Observation of Au(111) electrode surface structure in Bis(trifluoromethylsulfonyl) amid-based ionic liguid using surface X-ray scattering. Electrochemical communications, 13, Elsevier, p411-413, (2011).
- Sakaue,K., Tanaka,N., Takahashi,I., and Terauchi,H.,; Thin-film structures of epitaxial chromium on MgO(001) substrates by MBE. Acta Cryst. A64, C556-C557 (2008).
- Matsushita,K., Kitahara,A., Sakaue, K., Takahashi,I., Terauchi,H. and Doi,S., Effects of BaTiO3Overlayers Deposited on SrTiO3(001) on Its 105 K Phase Transition. Surface and Interface Analysis, 37, 145-148 (2005).
- V.A.Shuvaeva, I.Pirog, Y.Aduma, K.Yagi, K.Sakaue, H.Terauchi, I.P.Raevskii, K.Zhuchkov and M.Yu Antipin., The Local Structure of Mixed-ion Perovskites., J. Phys. Condens. Matter. Vol.15 pp.2413-2421