Magnetic ordering effects upon the optical spectra of rare earth compounds have been investigated in the molecular field approximation. The shifts and splittings of absorption lines of DAG below the Neel temperature are interpreted in terms of magnetic interactions between the Dy3+ ions and the finite shifts above TN are attributed to the presence of magnetic short-range order. A triplet structure of the absorption lines of DyAIO3 is interpreted as arising from an interaction with two nearest neighbor Dy3+ ions along the crystal c-axis. The absorption spectra of DyAIO3 measured as a function of the external field show evidence for metamagnetic transition. The exciton-magnon excitations (magnon-sidebands) and the co-operative optical excitation in the rare earth compounds are also discussed.
Results of measurements on the propagation characteristics of surface elastic waves excited on unpolarized PZT ceramic plates using interdigital arrangement of electrodes, under various external conditions, are reported. As external conditions, the effects of various gases, atomospheric pressure, humidity and temperature are discussed. These results show that the effect of temperature is the most striking. Furthermore, imformation on the attenuation of surface waves is presented. For input voltages up to 40 V, the logarithmic decrement depends upon frequency but not upon amplitude. The loss due to elastic hysteresis mechanism has been observed for input voltages higher than 50 V.
The optimum substrate temperature for preparing CdS films by means of solution spray was determined and it was found to depent upon the starting materials. When cadmium chlo ride and 1-3 dimethylthiourea were used as starting materials, CdS films with good crystal orientation could be obtained. The Hall mobilities of these films higher than 100cm2/V-sec. were obtained by an appropriate heat treatment in vacuum. When cadmium acetate and 1-3 dimethylthiourea were used, poor crystal orientation was obtained and Hall mobilities were only about 1_??_6cm2/V-sec. The difference in Hall mobilities may be due to crystal orientation.
Hall mobilities (μH) were measured on undoped and Cu-doped US single-crystals grown from the melt at the temperature range between 90°K and 300°K. The copper concentration is about 1017 atoms/cm3. At low temperatures, Hall mobilities of undoped samples are lower than those of Cu-doped samples. In Cu-doped sample quenched from 300°C, μH increased as a function of time at room temperature. This phenomenon is not observed in undoped CdS. These imply that in Cu-doped samples, μH is limited by donor-Cu dipole scattering, but not by impurity scattering.
This paper is concerned with an attempt to establish the correct theory of the so-called kinetic-energy correction and end correction of a capillary viscometer. By applying Newton's law of motion to the liquid within the main capillary, the correct general equation (14) for Poiseuille's law is obtained and it is found that the usual equation (16) for the law is only a special case of Equation (14). It is made theoretically clear that both the kinetic correction and the end correction depend exclusively upon the velocity distribution at the inlet end of the main capillary. Some experiments were carried out by placing an auxiliary capillary on the upstream side of the main capillary. The velocity distribution at the inlet end can be changed by replacing the auxiliary capillary with another one of different radius. It is observed that the experimental results agree fairly with the above theoretical consideration.
A new method is described in which the radial distribution of temperature in a circularly symmetric plasma can be immediately computed from the lateral distribution of the ratio of radiances of two spectrum lines without using Abel inversion. Comparison is made with the usual method of using the relative intensities of the two lines. On account of the unsteadiness of a plasma at atmospheric pressure, the ratio of radiances can be measured more accurately than radiance itself. As a result, the error involved in the temperature distribution computed by using the present method is smaller than one-tenth of that obtained by using the usual method, particularly at the outer layers of a plasma. Here, in order to examine the present method, the model used in Abel inversion by Pearce is used. This computation is made for six test curves of the ratio of radiances.
Methods are proposed for forming stigmatic images with as large a demagnification as possible by a three element quadrupole lens system, without increasing the ratio of the object and image distances. Their paraxial focusing characteristics are calculated based on a rectangular field model. Astigmatic virtual images are formed by an incident quadrupole singlet within the lens. A real stigmatic image of the virtual ones can be formed at a desired image distance by a quadrupole doublet behind the lens without changing the object distance or the construction of the lens system.