On the g-Value of Ferrimagnetic Resonance

We performed the quantum mechanical calculation of the effective g-value of three-spin-system in which there exists the exchange interaction among three spins of 1/2, of which one spin has a different g-value. The object of this paper is to analyse the simplest model of ferrimagnetic substances which have the unsolved problem concerning the determination of exact g-value. The present result can be expressed as follows : When the exchange interaction is positive, the effective g-value of the three-spin-system coincides with that of the classical calculation. But when the ferrimagnetic interaction exists, the effective g-value of this system is different from the result of the classical theory of ferrimagnetic resonance. This is caused by the characteristic of the three spin wave functions which are symmetric for ferromagnetic ground state but show asymmetry for ferrimagnetic state in exchanging each spin coordinate. And if this effect can be applicable in the same manner to the case of actual ferrite, for example Ni-ferrite, the effective g-value to be shown in the microwave resonance absorption must be expressed as g^* = 2g_+g_/3 On the other hand however the result of the classical calculation shows g^* =g_. Here g_ and g_ represent the g-values of Ni^_ and Fe^_ ions respectively. Of course, this relation must be reevaluated in the case of actual ferrites which have many electrons acting on one another with strong exchange interaction. But it may be pointed out that the determination of g-values in ferrites only from the classical point of view must be reconsidered

Paramagnetic Resonance of Ni(NH_4)_2(SO_4)_2・6H_2O and NiK_2(SO_4)_2・6H_2O at 47000 MC

Experiments on the paramagnetic resonances of two nickel Tutton salts were performed at 47000 MC and at room temperature. The crystalline field constants were determined and compared with the results obtained by Griffiths and Owen on the same salts but at lower frequencies ; for nickel ammonium salt, the result was in satisfactory agreement. but some differences between both the values were found in the case of nickel potassium salt. The crystalline field constants of the nickel potassium salt were found respectively to be D= -3.50±0.01 and E= -5.55±0.01

Paramagnetic Resonance of Two Iron Alums

Experiments on paramagnetic resonance were performed with two ferric ammonium and potassium alums in different magnetic dilution and at various wavelengths. The fine structure expected from the results of Weidner and others\u27 work^ could be observed satisfactorily. Furthermore, the splitting in the case of ferric potassium alum could be observed in a high magnetic diluted crystal

On the Phenomenological Theory of the Fine Exfoliating Disintegration

We performed the phenomenological calculation of the distribution function of numerous particles which are in the process of fine exfoliating disintegration. As is well known, the fine disintegration method is one of the most important methods to get fine powders of various material, and so the precise analysis of this mechanism is interesting not only as a problem of physics but also from the industrial point of view. We confined our problem within the phenomenological theory because of the lack of knowledge upon the microscopic nature of the fine disintegration on various materials such as metals. The present result may be expressed as follows : 1. The general distribution function of particles can be derived as a function of time and mass of particles. 2. The narrowing or broadening of distribution function which were observed experimentally can be explained respectively as the special stage of disintegration process. 3. The physical characters of materials such as brittleness toughness and elasticity have no serious effect on the shape of distribution function but merely affect the velocity of disintegration. 4. Disintegration process by Bond\u27s method (useful method for making the sphere of solid) is analized from the phenomenological point of view

On the Measurements of the Galvanomagnetic Effect in Semiconduetors at Microwave Frequencies

A convenient method for the measurement of the galvanomagnetic effects in semiconductors at microwave frequencies is described. The resonant cavity method is used for this purpose and the magnetoresistance of germanium at low temperatures is observed at 9800 Mc/sec

Dielectric Constant and Permeability of Various Ferrites in the Microwave Region

The dielectric constant ε and permeability μ of ferrites have already been studied at audio and high frequency region, but they have scarcely been measured in the microwave region. We have determined ε and μ on various simple polycrystalline specimens of magnesium, copper, cobalt, nickel and manganese ferrites quenched or slow・cooled from high temperatures at the wave-length of 6.6 cm by observing changes in Q-value and frequency shift when a thin disk formed specimen, whose diameter is 20 mm and thickness is 1 mm or 1.5 mm, attached on a supporter, was inserted in the rectangular cavity (TE_ mode) at the positions of the electric and magnetic field maxima, respectively. From these measurements, both real and imaginary part of e and p were determined from the formula which were derived by expanding the field in the cavity by using orthogonal function introduced by Slater

ジバチュウ ノ スイソ ゲンシヨウ レイキシ ノ ハドウ カンスウ ニ ツイテ ノ セツメンスウ ホゾンソク ノ ダトウセイ

Magnetoabsorption experiments on the A exciton in InSe have been performed in search of a unified correspondence relation between low and high magnetic field levels of a hydrogenlike state. Results show that the nodal-surface conservation rule of Shinada et al. is a more appropriate representation of this relationship than the so-called noncrossing rule.磁場中の水素原子の固有状態は解析的に解くことが不可能であるために、物理学上の永年の問題となってきた。磁場の強さが無限大の極限では無磁場のときとは量子数の全く異なる漸近解を持つことが知られているが、この強磁場極限準位に無磁場状態がどのように接続するかという疑問が問題の核心である。本研究では、InSeの励起子が物理的に理想に近い水素原子類似体であり、かつ固体効果によって水素原子に対するよりも数桁低い磁場で強磁場極限に到達しうることに着目して磁気光吸収を測定した結果、準位の接続に関して波動関数の節面数保存仮説を強く支持するデータが得られた