Development of Diamagnetic Resonance
Grant-in-Aid for General Scientific Research (C)
|Allocation Type||Single-year Grants|
|Research Institution||Osaka University|
YOSIDA Taturu Low Temperature Center, Assistant, 低温センター, 助手 (90127316)
DATE Muneyuki Department of Physics, Faculty of Science, Professor, 理学部, 教授 (80028076)
YAMAGISHI Akio The Research Center for Extreme Materials. Associate Professor, 極限物質研究センター, 助教授 (10006273)
|Project Period (FY)
1989 – 1990
Completed(Fiscal Year 1990)
|Budget Amount *help
¥1,800,000 (Direct Cost : ¥1,800,000)
Fiscal Year 1990 : ¥300,000 (Direct Cost : ¥300,000)
Fiscal Year 1989 : ¥1,500,000 (Direct Cost : ¥1,500,000)
|Keywords||diamagnetism / anisotropic susceptibility / magnetic resonance / polymer / biopolymer / molecule orientation in magnetic field / superconducting filament|
It is well known that all substances shows diamagntism. In polymeric and biopolymeric substances, the diamagnetic susceptibility becomes anisotropic due the alignments of constituent diamagnetic molecules such as peptides and such polymers are easily oriented in an applied magnetic field so as to minimize the field-induced magnetic energy. The orientation phenomenon is considered as that of the 'field-induced diamagnetic moment' to the field direction. The research project aims to realize the idea proposed by one of the investigator, Professor Date. That the moment of inertia of a polymeric sustance is made to oscillate about the center of mass by applying the oscillatory magnetic field to the diamagnetic moment. The resonance condition exists in the oscillation and the name of this project comes from the condition.
We have achieved the installation of experimental apparatus and the observation of diamagnetic resonance. The principle of diamagnetic resonance can be confirmed.
We have als
o developed the new measuring method of small magnetic susceptibility by using the strong field gradient produced by a pulsed magnet. The maximum sensitivity of the new method is estimated to be higher than that of SQUID magnetometers. We can measure the anisotropic susceptibility and estimate the resonance frequency.
Our research for two years consists of
1. Having made the high sensitive optical detection system to observe the resonant orientation phenomenon.
2. Having made the modulation coil which can produce modulation field perpendicular to the static field. Frequency sweep of modulation field is easily done by controlling from a personal computer.
3. Having made the cryostat to hold the sample cell.
4. Having Checked the performance of apparatus by using the superconducting filaments. of NbTi as sample.
5. Having Observed the resonance on several mineral substances with larger anisotropic susceptibility. The fine particles of a sample are suspended in water and the absorption of laser light is observed in the frequency region lower than the resonant frequency. The intensity of absorption becomes weak as the applied static field is set strong and resonant frequency shifts to lower frequency region, consistently explained with the forced oscillation theory with a large damping term. Less
Research Output (10results)