Overview of the research activity

   The research activities of this laboratory have mainly concerned to the physicochemical phenomena for molecules and molecular assemblies, which can be observed by the magnetic resonance techniques. As a result a good worldwide reputation has been established for this laboratory especially on the magnetic resonance spectroscopy. Currently, however, we are gradually shifting the focus to the material chemistry in order to make a direct contribution to industry. For example we are developing a method to control chemical reactions by employing an inorganic mesopore material as a reaction media. In addition, techniques for fabrication and micro-processing of crystalline films and multi layered films have been pursued by using the pulsed-laser ablation method.

Research Theme

1. Synthesis of inorganic mesopore materials and their application to control chemical reactions
2. Study on dynamics in mesoscopic region taking advantage of the electronic spin as a probe
3. Fabrication and micro-processing techniques of crystalline films
4. Development of ESR techniques and apparatus for evaluation of electromagnetic qualities of crystalline films
5. A study of hybrid devices coupled by elementary excitations relating superconductivity and magneto-resistance

Staff

* a member of the editorial advisory board of "Applied Magnetic Resonance (Springer Verlag)"
** a guest professor of Gifu University, Graduate School of Technology (Material Science of Functional Films)

Details of the study

1. Synthesis of inorganic mesopore materials and their application to control chemical reactions.

   Mesoscopic materials, such as modificated MCM-41, are prepared by employing an organic molecular assembly as a template. We make an apparatus designed for a photochemical reaction to proceed in a mesoporous material and search a method to control the reaction, e.g. by manipulating the electron spins on the short-lived intermediate radical pair with a microwave pulse under a magnetic field.
Recent Publication: "Benzene cation radical in mesoporous silicate: EPR detection of unusually stabilized Jahn-Teller distortion" (Phys. Chem. Chem. Phys., vol.1 in press (1999)).

2. Study on dynamics in mesoscopic region taking advantage of the electronic spin as a probe

   In this study, correlation between the two spins (spin pair) of the intermediate radical pair is studied, which is produced in a photochemicalreaction and is trapped temporarilyin a mesoscopic space. A new quantum mechanical method "spin manipulation technique"has been proposed to control this reaction. This technique has been extended as a new ESR technique called product yield detected ESR(PYESR) and is applied to study the dynamics of an electron spin interacting with the orbital angular momentum, other spins, and magnetic fields, and so on as well as the dynamics of micelle.
   Structure and characateristics of mesoporous materials are studied with the magnetic resonance techniques for the development of a new line of materials having structures with mesopores.
Recent Publication: "Reaction Yield Detected ESR and Its Application to Control Chemical Reaction", in Dynamic Spin Chemistry, ed. S. Nagakura, H. Hayashi, and T. Azumi, Chap. 8,�@Kodansha Scientific (1998).

3. Fabrication and micro-processing techniques of crystalline films

   It is necessary to fabricate high quality films and multi-layers with flatness and thickens in a nano-meter scale and to develop new techniques in the fabrication and micro-processing for developing new type electro-magnetic devices utilizing quantum tunneling effects and spin-control. The pulsed laser ablation-deposition(PLD) technique is investigated as a preparation and processing method of the thin films, since it has advantages in controlling the atomic composition of the films and in the fabrication of multi-layers. We have studied mainly using Nd:YAG solid state laser and developed a new powerful PLD technique and apparatus for fabrication of films using ultra-vacuum ultraviolet lights, which are produced by Raman effect of hydrogen gas at a high-pressure. Further improvement of the appratus and oscillation of laser light with shorter wavelength are investigating.
Recent Publication: "Preparation of thin epitaxial YBCO films by Ablation using Fourth Harmonics of Nd:YAG Laser", Physica C 282-287, (1997) 577; Patent Appl. No: H10-296145

4. Development of ESR techniques and apparatus for evaluation of electromagnetic qualities of crystalline films

   Flux-dynamics in ceramics superconductors has been studied using an improved ESR spectrometer. The study revealed that it was possible to detect the flux-penetration and trapping process at Josephson junctions and to evaluate the magneto-resistance at the junctions. A new ESR technique is further investigating for measurement and evaluation of electromagnetic qualities of the films and multi-layered devices which are made of superconductors and giant magneto-resistance(GMR) materials via quantum-flux resonance and spin-wave resonance.
Recent Publication�F "Detection of Quantized Flux Penetration into Very Small 0-type Josephson Links in Bi2Sr2Ca1Cu2Oy Single Crystals using ESR Spectrometry", Phys. Rev.B, 55, (1997)14479; Patent No. 2569424

5. A study of hybrid devices coupled by elementary excitations relating superconductivity and magneto-resistance

   A basic study of hybrid devices has been started in order to develop Josephson junction devices, spin-controlled superconducting devices and GMR devices by fabricating multi layers of superconductors, dielectric substances, insulators, and magnetic materials in a nano-meter scale and by coupling elementary excitations such as superconductivity or conducting electrons with spins and magnons.