Pressure effects on the Curie temperature Tc and the spontaneous magnetization at 0K, σ0, are reviewed systematically. The materials concerned are Ni-, Fe- and Co-based transition metal alloys and the intermetallic compounds between rare earth metals including Y, La and Th, and Fe, Co and Ni. Experimental results of the pressure effect on Tc, ΔTc/Δp, for the alloy systems are similar to the results of the compound systems, when ΔTc/Δp is considered to be a function of Tc. The results of the pressure effects on both Tc and σ0 are analysed on the basis of the itinerant electron model. Finally the pressure effects on the magnetocrystalline anisotropy and the internal field, and some materials for which the pressure effect is to be investigated are briefly presented.
A bimetallic vacuum gauge of temperature-difference type is based on the measurement of the thermal conductivity of the residual gases. The main part of the differential bimetallic thermometer, here descrived is, composed of a helical, and a spiral coil in series, of which the deflections are in opposite direction, and the angular, deflections for the same temperature change are equal to each other. The helical coil functions as a heating element while the spiral coil is a non-heating element, and the two coils are connected together by a tubular rotating shaft of poor thermal conductivity. A suitably adjusted compound bimetallic differential thermometer directly gives accurate temperature differences. In this work, two types of vacuum gauges have been experimentally examined. In the first type, the heating current flows through the helical coil itself. In the second type, the heating is supplied by a resistance wire in contact with the outer surface of the helical coil. The measurable vacuum range is about from 5×10-2 to 1×102 Pa. The measurement can be carried out with a temperature rise of the element of less than 60 Kelvins.
The Rankine-type capillary viscometer has several merits; (1) the handling and measuring is simple, (2) the amount of sample gas is small, (3) it is unnecessary to measure the pressure difference between the ends of the capillary. The measuring principle and various corrections in the viscosity measurement under the ordinary condition with this viscometer is analyzed theoretically. The most considerable problem is the effect of surface tension of mercury. The surface tension acts on the mercury pellet and affects the pressure difference between the ends of the capillary. In order to evaluate and correct this effect, falling velocities of the pellet are measured for one pellet and also for two segments which are divided from the one pellet. The instrumental constant of this viscometer is calibrated by using the value of nitrogen viscosity at 1.01×105 Pa [_??_ 1 atm], 25°C. Viscosities of nitrogen measured at other temperatures (12.5°C, 37.5°C, 50.0°C) are compared with other published data. From experimental results the accuracy of this viscometer is estimated to be about ±0.17%.
A high pressure CO2 laser was developed using an electron beam controlled discharge. Successful performance at laser gas pressures up to 15 atmospheres was achieved. The pumping input energy could be controlled up to 300J/l•atm by adjusting a gun voltage for a constant E/P of the main discharge, where E is the applied electric field strength and P the laser gas pressure. The collisional broadening coefficient of a rotational laser line was measured to be 4.6 GHz/atm. The characteristics of passive mode-locking was investigated. The individual pulse width of a mode-locked pulse train decreased towards the latter part of the train. The physical and technical problems for stable and reproducible generation of ultra-short pulses are discussed. Using a hot-hole photoconductive detector, the measured shortest pulse width was 670ps which was limited by the time response of the measuring system.
A simple approximation formula for the electron current density distribution in the irradiation field of an electron accelerator was found as a function of the physical parameters concerning irradiation. Calculation is based on the mean squared scattering angle derived from the simple multiple scattering theory, in which scattering in the beam window and air, electron transmission coefficient and beam scanning are taken into consideration. The electron current density was measured by the method of charge absorption in a graphite absorber set in air. Except at large scattering angles, the calculated values agree with the experimental values within about 10% for calculated mean squared scattering angles of 0.089-0.29. Periodic variation of the current density of scanning beam and the application of this formula to dose evaluation are also described
Electrochromism in as-evaporated Er-diph-thalocyanine (ErPc2H) film was measured with SnO2|ErPc2H| 0.1N, KCl aq.| Pb cell. In the case of SnO2(+)-Pb(-)polarity, the change of color to yellow-tan and orange began to develop in the part adjacent to the electrolyte solution. While, in the case of SnO2(-)-Pb(+)polarity, the change of color to blue and violet first appeared in the part adjacent to SnO2 electrode. In the former case, the change of color is attributed to the formation of ErPc2H-anion complexes by injection of anions of electrolyte. In the latter case, the change of color is due to the reduction of ErPc2H complex at the SnO2 electrode.