|Budget Amount *help
¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 1994 : ¥300,000 (Direct Cost : ¥300,000)
Fiscal Year 1993 : ¥1,800,000 (Direct Cost : ¥1,800,000)
The Project has been developed for the investigation of Hall effect in the liquid state ; 1) false signal generated in the measurement through Two-frequency ac method, 2) Nonlinearity affecting the Hall effect in the liquid state, 3) Ac-dc method and its application. The results are as follows,
1) The false signal through the two-frequency ac method is produced in the sample or the measuring system including amplifiers, especially at the interface between a electrode and sample solution. The false signal increases with an applied magnetic field. The signal accormpanies many harmonic trains of Hall one. The polarity sign of the signal does not correspond to that of the applied magnetic field.
2)The variation in resistance of 10^<-7>/G corresponding to the applied magnetic field appears due to the Lorentz force in the liquid state. The value in solid state or semiconductor sample is neglected or within measuring tolerance. An incorrect signal corresponding to the square of magnetic field appears in the liquid of metals, even electrolyte solutions, and disappears when the metal samples are solidified. However, it appears in the solid state of ferromagnetics, Fe, Ni and semiconductor film, lnSb.
3)The false signals are not observed through our ac-dc method even if there existed nonlinearities, besides the method shows the sign polarity corresponding to the magnetic field polarity, therefore the Hall signal is easily distinguished from the false signal. Another incorrct signal were decreased to thermal noise level with increasing the frequency of sample current over 1 kHz, Ture Hall signals with polarity sign were obtained in the liquid states.
Measring of true Hall signal nearby DC,The cause of the incorrect signal corresponding to square of applied magnetic field and its mechanism, Auto-matic evaluation on measured Hall signals, should be expected to study more.