Two new methods to find the basic vector correspondence matrix of the coincidence site lattice for two phases have been developed by means of theory of matrix and elementary theory of numbers. Based on these methods the three equations which are applied to find a coincidence site lattice have been incoporated into a single one so that the problems concerning the composite lattice of two phases wit...
Universal and straight-forward formulas for finding coincidence coefficients of space lattices of two phases and their plane lattices having a coincidence site lattice relationship are derived by means of elementary theory of numbers. The coincidence coefficient of a space lattice is α2(3)=1/|C(1)| and that of their plane lattices are α2(h)= (H(2)C(1)/|C(1)|, C(1) being a basic vector corresponden...
The internal friction peak associated with the process of martensite and reverse martensite transformation in Au-Cd alloy were measured by torsion pendulum. There is a linear relation between the peak value and rate of heating. The stable peak (heating rate=0) is much higher than that of Fe-Mn alloy and the internal friction value is independent of frequency which is characteristic of static hyste...
A phase diagram of the alloys of the Al-Cu-Ga ternary system has been determined by using X-ray analysis.The isothermal section at room temperature was found to consist of eleven single-phase regions (i.e. α, γ2, γ′, δ, ζ1, ζ2, η2, θ, θ′,αA1 and Ga), fourteen two-phase regions (i. e.α + ζ1, α+ γ2, α + γ′, γ2 + γ′, γ′+ ζ1, γ2+δ, γ′+δ,δ +ζ2, ζ2+η2, η2+θ,η2+ θ′, γ′ + θ′, θ′+ Ga, and θ + αA1); and nin...
A new graphic method has been developed for indexing Debye-Scherrer photographs, Utilizing the sin2θ values of three low angle reflexions and the density of the crystal investigated, a series of conditional lines and equiatomic curves are drawn in the A-C space, where A=λ2/4α and C=λ2/4C2 in the tetragonal system, and A=λ2/3a2 and C=λ2/4c2 in the hexagonal system. The conditional lines are a manif...
The pseudo quaternary system phase diagram of Y2O3-Fe2O3-Bi2O3-PbO·0.2B2O3 is obtained and used. Single crystals of the ferrimagnetic garnet Y3-xBixFe5O12(O≤x≤ 1.2) are grown by using Bi2O3-PbO-B2O3 flux systems. The dependences of the content Bi (x) in the single crystals of Bi-YIG on the compositions of the solutions arediscussed.
We present an analysis of further physical consequences of the Q-approximation and a discussion on the number of closed paths taken into account by this method. A counter example ("Incense" graph in Fig. 3) shows there exists no rotation angle mapping which would give the proper number of closed paths on a 3-dimensional lattice.
Several principal conclusions for the so-called core-wing-ratio method for measuring the roughness of diffusing surfaces with laser beam based upon the previous papers are given. The method for determining the coefficients in the probability density function P(h) of random height is given, following the emperical relation R2=5Ra. For P1(h)={e(-b(|h|/hm)) ,|h|≤hm 0,|h|>hm and P2(h)=e(-a2(h/hm)2) ...
It is suggested that far-infrared radiation can be generated by difference-frequency mixing of surface waves on an interface between metal and nonlinear crystal. Particularly, the power of FIR generated on Al-GaAs interface is catculated in the case of noncollinear phase matching. In this calculation, the imaginary part of dielectric constants is considered.
We suggest a new efficient method of laser tuning: the principle of tuning and amplification by self-injection. By this means, the influence of tuning elements on the laser output power is reduced to a minimum, that is, the tuning efficiency can approach 1. This provides a possibility for laser outputs of both high power and narrow bandwidth to be obtained with one laser oscillator. The theoretica...
The chlorine chemisorption geometry fcr both Si(lll) and Ge(lll) surface is considered. Previous theoretical calculations could not give the difference between Cl chemisorbtion on Si (111) and Ge(lll), which was shown by the effects observed in the photoemission with polarized radiation. In this paper the chemisorbed site is determined by the minimization of the total energy calculated by the char...
In this article, the Fresnel-Kirchhoff diffraction formula is used to study the interference phenomena described previously in [1]. The expression for intensity distribution of the interference pattern is derived and the maximun positions obtained. A physical interpretation of the interference phenomena is given.
The chemisorption of Al on the GaAs(ll0) surface is studied by using the charge self-consistent EHMO method. In comparing the two different mechanisms of adsorption, the more stable mechanism is determined by the configuration which gives a lower energy, and it is suggested from the present study that Al will substitute the surface Ga atoms, while the latter will be adsorbed on the dangling bonds ...
The problem of solving the Dirac equation in a Kerr space-time has long been unresolved. In 1976, S. Chandrasekhar solved the decoupling problem of the Dirac equation with non-zero rest mass in a Kerr background, thus provided the possibility of attacking the problem of the Hawking evaporation of Dirac particles. In this paper, starting from Chandrasekhar's results, we find the solution of the Dir...
On the basis of the pressure Px at 0 K deduced by the present authors in the paper [1], using Debye solid model and considering the thermal pressure of electrons, we obtain the equation of state for metals at high temperature and pressure. Combining this equation with Hugoniot equation we can calculate the Hugoniot curves which can be compared with experimental data. The Hugoniot curves for five s...
Using acousto-optic Q-switched Nd3+: YAG laser as a source of fundamental beam, we measured the SHG scan vs temperature in LiNbO3 and BNN single crystals. There are usually two peaks appearing on the SHG scan curves for the striae region, at the same time two NPM hollow cones of SHG light may be observed in one to one correspondence.One of the two peaks in the polydomain striae region of LiNbO3 di...
In this paper, we studied the birefringence topography of bismuth germaniun oxide which hare a strong natural optical activity. It is discovered that the natural optical activity of the crystal may be compensated completely with a reflection polarised light microscopy so that the birefringence images of dislocations and subboundries were observed. The Burgers vectors of dislocations were found to ...
The definition and an X-ray determination method of the degee of preferred orientation of ferroelectric ceramics with layer type structure after hot-pressing procedure are presented. The degree of preferred orientation can be obtained by merely determining the ratio of diffraction intensity of any one or more (00l) lines before and after hot-pressing procedure. Taking the mixed bismuth oxide compo...
An electrostatic field is applied along the s-axis of a-LiIO3 single crystal. Let a beam of light pass through the crystal along the direction of the crystal 2-axis, almost no change of the transmission photograph is found; when the beam of light passing through the crystal deviates from the direction of the crystal z-axis, some patterns appear on the transmission photograph. In this work, the spe...