Bemerkung zur Arbeit von L. ?pa?er: Die Struktur der Oberfl?chlichen Abschlussbereiche in den (100) Ebenen in Eisen [4]

Ohne Zusammenfassung

---

L. paek (100)

     

The quantum theory of the spontaneous magnetization of ferrimagnetics,anti-ferromagnetics and thin films with arbitrary spin at high temperatures

Using Van Vleck's modification of the Heisenberg theory of ferro-magnetism for substances with arbitrary spin per atom, a generalization of the theory is given for the case of ferrimagnetics, anti-ferromagnetics and thin films with an arbitrary number of sub-lattices and with arbitrary spin per atom. The exchange part of the energy operator is formulated by means of rotated spin operators. The theory contains the quantum-mechanical generalization of non-quantum theories given by Néel and later generalized by Yafet and Kittel. It also contains the theory of thin films proposed recently by the author. The magnetization laws are completely analogous to the relations derived from the theory of molecular fields. The constants of the molecular fields are interpreted by means of exchange integrals. For the special case of spin S=1/2the theory agrees with the results of the work of Vlasov and Imuchametov for ferrimagnetics and anti-ferromagnetics and with the author's for thin films.

---

,

, , , . . - , . , . , . . S=1/2 .

     

The change in primary extinction during decomposition of a super saturated solid solution 1. System Al-Ag

On the basis of the correlation of diffraction data (intensity and width) of a precipitate with the intensity of reflection of a matrix solid solution it is shown that the change in primary extinction during the decomposition of a solid solution of Agin Alis caused by the precipitation of the phase Ag₂Aland not by the production of lattice defects (zones, stacking faults).

---

I. Al-Ag

( ) , Ag Al Ag₂Al, ( , ).

---

---

Reported in part at the VIth Scientific Technical Conference on the Application of X-rays held in Leningrad in 1958.

---

The author thanks M. Mikovský for preparing the single crystals of the alloy Al-Ag having a high primary extinction and J. Laek and Prof. J. Bedná for carefully checking their homogeneity and chemical composition.     

A note on the divergence of a series for multiple beam interference in a thin metallic film

The paper deals with the problem of the anomalous divergence of an infinite geometric series of complex amplitudes, pointed out by Berning. It is shown that the paradox is of a formal mathematical nature and has no consequences for multiple beam interference as a method of derivation.

---

, . , - .

     

An attempt at a phenomenological interpretation of the influence of a polarizing field on piezoelectric resonators

The change in frequency of quartz piezoelectric resonators in a d-c electric polarizing field cannot be explained merely by a change in the dimensions of the resonator due to the polarizing field caused by the inverse piezoelectric effect and electrostriction. We are forced to admit that the elastic constants also change in a polarizing field. A phenomenological interpretation of the influence of a d-c electric polarizing field on the frequency of quartz resonators is proposed here, based on newly introduced quantities characterizing such a change. In conclusion it is shown in what way the quantities, on which the phenomenological theory is based, can be determined experimentally.

---

, . , . , , . , , .

---

---

The author would like to thank Dr. J. Tichý for carefully reading the paper, for valuable discussion and numerous remarks on style and subject matter, which greatly helped to improve the text. He is also indebted to V. Janovec, C. Sc., for some new aspects and the exceptional interest with which he reviewed the paper.     

ТЕМПЕРАТУРНАЯ ЗАВИС ИМОСТЬ ТЕРМОЭЛЕКТРОДВИЖУЩ ЕЙ СИЛЫ СЕРОГО ОЛОВА С ПРИМЕСЯМИ КАДМИЯ

- , - —183 —10 °.     

Die halbleitende Vebbindung SiTe

Ohne Zusammenfassung

---

SiTe

     

Anti-parallel ferroelectric domains in surface space-charge layers of BaTiO3

It is shown on simplified models of a surface space-charge layer of a single crystal of BaTiO ₃ that in the surface region, in which the direction of the electric field is opposite to the direction of spontaneous polarization inside the crystal, anti-parallel domains can exist. The dimensions of these domains are determined. The use of the results obtained is proposed for interpreting the microrelief of the etch figures and for explaining the different phases of the polarization reversal process of a single-domain single crystal of BaTiO ₃.

---

BatiO₃

BaTiO₃ , , , . . BaTiO₃.

---

---

The author would like to thank J. Kaczer, Z. Málek and V. Dvoák of the Institute of Physics, Czechoslovak Academy of Sciences, for valuable remarks on this paper and H. Havlíková for carefully carrying out the numerical calculations.     

The influence of elastic deformation on the magnetostriction constant of nickel and iron-nickel alloys

The dependence of the magnetostriction constant of different materials in the form of a wire on the elastic elongation was measured. With pure nickel the magnetostriction constant is independent of the elastic deformation. All three alloys of iron and nickel and the triple alloy Fe-Ni-Co exhibit a linear dependence on the deformation, which differs for different crystallographic texture. In two iron-nickel alloys the dependence of the magnetostriction constants of the single crystal on the elastic deformation was calculated from measurements on polycrystals having different crystallographic textures. In the triple alloy Fe-Ni -Co a considerable linear decrease in the volume magnetostriction with the elastic elongation was also found. The observed changes can be explained by assuming the influence of the lattice deformation on the spinorbital interaction in alloys.

---

-

. . - Fe-Ni-Co , . - . , Fe-Ni-Co . - .

---

---

A preliminary report on some of the results of this paper was given at the conference on magnetism in Kyoto (Japan) in September 1961.

---

In conclusion the authors thank Z. Frait C. Sc. and S. Libovický for remarks, J. Míová for help in the measurements, members of the chemical department of our institute for annealing and analyzing the samples and members of the Metal Research Institute in Panenské Beany for their exceptional helpfulness in preparing the wires.     

Die Abhängigkeit der Banddurchbiegung von der Lage der Stufenversetzung

Zusammenfassung Es wird die Lösung des Spanungszustandes im unendlichen Band mit einer lotrecht zur Bandebene stehenden Stufenversetzung und mit einem Burgerschen Vektor, der parallel mit der Bandachse verläuft, unter der Voraussetzung der klassischen mathematischen Elastizitätstheorie wiedergegeben. Weiter wird der Ausdruck für die Gesamtdurchbiegung des Bandes in Abhängigkeit von der Lage der Versetzung und für die Durchbiegung bei einer allgemeinen Verteilung der Versetzungen, die durch eine kontinuierliche Verteilung approximiert ist, abgeleitet.

---

, , . , .

---

---

Für die wertvolle Diskussion und einige Hinweise danke ich dem Kollegen Jan Kaczér, für das Lektorieren der Arbeit dem Kollegen Bohdan esták.     

The elastic coupling between longitudinal and transversal vibrations оf isotropic rods II. Rods of circular cross-section

The new approximative method for calculating the frequencies of longitudinal vibrations of isotropic homogeneous rods described in part I. is used for rods of circular crosssection. Similarly to the rods of rectangular cross-section there does not exist any dead zone of frequencies.

---

II.

, I. (. . 366), . , , .

     

The lattice spacings of equilibrium solid solutions of silver in aluminium

This paper describes the measured dependence of the lattice spacings of equilibrium Al-Ag solid solutions on temperature and composition. The form of the lattice spacing composition curve is found to differ considerably from that for the supersaturated Al-Ag solid solutions. The differences between the spacings of equilibrium and quenched Al-Ag solid solutions plotted against the electron concentration yield a curve similar to that constructed from the analogous measurements on Al-Zn given by Ellwood. The differences can be attributed to the influence of changes accompanying the increased solute clustering introduced by quenching the solid solutions into the supersaturated state.

---

Al-Ag . , Al-Ag . Al-Ag, (. . , ), Al-Zn, , . , .

---

---

The author wishes to express her thanks to Ing. J. Lagek for his care in carrying out the chemical analysis of the aluminium-silver alloys. The careful density measurements of these alloys made by J. Bednfi [are greatly appreciated.     

The application of the thermodynamics of irreversible processes to welding arcs

The self-regulation of an inert gas shielded metal welding arc is dealt with briefly. A thermodynamic equation is derived for the self-regulation of such an arc.

---

. .

     

On the photo-electroluminescence of ZnS-Cu

The influence of weak ultra-violet irradiation on the brightness waves of electroluminescence is investigated for two types of ZnS-Cuphosphors. The observed effects (increase in brightness in the primary peak and its phase shift, the disappearance of the secondary peak) are explained on the basis of present-day conceptions on electroluminescence.

---

ZnS-Cu

ZnS-Cu. ( , ) .

     

Electron impact ionization. The probability of occupying states after ionization

The probability function of occupying states with a definite energy in the conduction band after collision in the process of electron impact ionization is calculated. The valence band is assumed of finite width. Several cases of the primary energy and the effective mass in the valence band are examined.

---

.

. . . , , , . , . . , , .

---

---

This work was begun at the Institute of Technical Physics of the Czechoslovak Academy of Sciences in Prague. The author wishes to thank the Director of that Institute for the possibility of working there and especially Dr E. Antoník for suggesting the problem and for helpful discussions.     

The elastic coupling between longitudinal and transversal vibrations of isotropic rods I. Rods of square and rectangular cross-section

A new approximate method for theoretically calculating longitudinal vibration frequencies of isotropic homogeneous rods of square and rectangular cross-section is given. We divide a three-dimensional longitudinal vibration into three one-dimensional ones; the coupling between the principal strains in question is assumed to be linear, similarly as in the static case of simple tension. The coupling between the deformations is realized by variable coupling parameters or depending on the order of vibrations (contrary to Rayleigh's correction where Poisson's ratio is the coupling parameter). These parameters are defined by the condition that the corresponding frequency must be minimized (stationary).Up till now Giebe and Blechschmidt [2] have given the best approximate method of calculation. The series of their calculated frequencies corresponds to the measuredones nearly as well as the frequencies calculated by us. The theory described here, however, contains a richer spectrum of frequencies and at the same time explains the frequencies measured in the range of the so-called dead zone, which is the weak point of Giebe's and Blechschmidt's theory.

---

I.

. ; , . , ( , ). , ( ). [2]. , , . , , , , . . , .

     

Bemerkung zur Theorie der Elektrolumineszenz in ZnS-Kristallen

Zusammenfassung Nach Zalm sind die Kristalle von ZnS mit einer dünnen Halbleiterschicht bedeckt, aus der auf Grund des Tunneleffekts Elektronen in den Kristall eindringen können. Im vorliegenden Artikel wird vorausgesetzt, da die Elektrolumineszenz bei der Rekombination dieser Elektronen mit den ionisierten Aktivatorzentren eintritt, die sich im Kristall zu Beginn eines jeden Zyklus vorfinden, und die Folgen dieser Voraussetzung werden mit den experimentell erhaltenen Daten verglichen.

---

ZnS

ZnS , . , , ; .

---

---

Dieser Artikel entstand aus einer Diplomarbeit, die im Physikalischen Institut der Tschechosl. A. d. W., Prag, ausgearbeitet wurde.

---

Abschlieend möchte ich RNDr. Miroslav Trlifaj für seine zahlreichen wertvollen Hinweise wie auch für sein Interesse an dieser Arbeit danken.     

Новый тип филътра С дв ойным лучепреломлен ием

, , , . .     

The perminvar effect and magnetic after-effect in magnesium manganese ferrite

An unstable perminvar effect was found in magnesium manganese ferrite at a temperature of –195°C and its connection with the magnetic after-effect was investigated. The analysis carried out on the basis of Néel's theory showed that both effects are a result of the same diffusion process. The experimental results also show that 180° Bloch walls are displaced when the sample is magnetized.

---

-

- – 195° C qe, , . , - . , 180- .