372595870

JPRS-UMS-92-003 16 March 1992

ANALYSIS, TESTING

with the help of difTerential thermal analysis (DTA) in helium at a temperaturę of up to 2,500°C and on the basis of data of derivative thermal analysis (PTA) in the air at temperaturę of up to 3,000*0 with the help of the helium unit. The projection of the liquidus surface of the temary system upon the concentration triangle piane and the constitution diagrams of polythertmal cross sections of the temary system are plotted. The analytical results confirm the presence of a minimum on the binary system’s liquidus curve at a temperaturę of 2,050°C and show that the temary system's liquidus surface consists of three primary phase crystallization domains; the max-imum liquidus surface temperaturę is equal to the melting point of the sample containing 90% (mol.) of Zr0₂. Figures 2; references 7: 4 Russian; 3 Western.

Magnetoelectric Properties of Piezoelectric and Magnetostrictive Materials’ Mixtures With Polymer Binder

927D0068R Moscow IZYESTIYA AKADEMII NAUK SSSR: SERIYA NEORGANICHESKIYE MATERIAŁY in Russian Vol 27 No 12. Dec 91 pp 2678-2678

[Article by T.G. Lupeyko, S.S. Lopatin, I.V. Churikova, I.B. Lopatina, Rostov State University]

U DC 537.228.1

[Abstract] The mixtures of piezoelectric and magneto-strictive materials which serve as the active basie ingre-dient of hybrid composites, display the magnetoelectric effect (ME), and are used in instruments for recording static and altemating magnetic fields, in frequency dou-blers, sensory buttons, and shaft speed-to-code con-verters are discussed and data on the properties and composition optimization of mixed magnetoelectric composites with a polymer bonding agent are presented. The PRK-1 sintered piezoelectric ceramic madę from lead zirconate-titanate with an addition of cadmium tungstate (an analogue of the TsTS-36 commercial product) was used in the experiments; the relative dielec-tric permittivity, dielectric loss tangent, radial coefifi-cient of electromechanical coupling, thickness coeffi-cient of electromechanical coupling, piezoelectric modulus, piezoelectric sensitivity, and speed of sound were measured. The concentration dependence of the dielectric permittivity, piezoelectric modulus, dielectric loss tangent, and piezoelectric sensitivity are plotted for a sample containing 75% of the mixture with ferrite and 25% fluoroplastic while the dependence of the magnetoelectric coefficient on the static magnetic bias field and the ferrite concentration is plotted for a sample containing 75% of the mixture with ferrite and 25% of fluoroplastic. The experiments were conducted in a unit at the Vitcbsk branch of the Solid State Physics Institute at the Belarus Academy of Sciences. Although the PKR-1 composites are inferior to sintered ceramic materials with respect to their magnetoelectric coefficient, they can be used when high sensitivity is not required of the transducer; in addition, the new composites are charac-terized by ductility and machinability. Figures 2; references: 1 Western.

Phase Composition and Photoconductivity of TIIn,__xDy_xS₂ Crystals

927D0068P Moscow IZYESTIYA AKADEMII NAUK SSSR: SERIYA NEOR GA NICHESKI YE MATERIAŁY in Russian Yol 27 No 12, Dec 91 pp 2657-2658

[Article by E.M. Kerimova, G.B. Gasymov, F.G. Mag-erramova, R.A. Aliyev, Physics Institute at the Azeri Academy of Sciences]

UDC 546.683-682.644.15

[Abstract] TlIn_l._xDy_xS₂ crystals with a monoclinic sym-metry as well as other modifications are investigated by the X-ray phase analysis method; Debye powder pattem diagrams of Bridgeman synthesized ground Tlln,_ xDy_xS₂ samples are plotted in Cutf_a-radiation; diffrac-tion pattems of TlIn,._xDy_xS₂ are summarized and the interplanar spacing data are presented. An analysis dem-onstrates that the TlIn,__xDy_xS₂ samples are single-phased and that diffraction reflections are uniquely induced on the basis of the monoclinic P-phase. The change in the TlIn,._xDy_xS₂ lattice celi parameters as a function of x, i.e., the number of Dy atoms in the molecule, and spectral photoconductivity distribution curves of TlIn,._xDy_xS₂ and TlInS₂ single crystals at 300K and 77K are plotted. The forbidden gap width of the above single crystals are equal 1.8 and 1.9 eV and 2.38 and 2.61 eV, respectively, at 300K and 77K. Figures 2; tables 1; references: 4 Western.

Effect of Magnetic Field on Residua! Impurity and Dopant Distribution in InSb

927D0068N Moscow IZYESTIYA AKADEMII NAUK SSSR: SERIYA NEORGANICHESKIYE MATERIAŁY in Russian Yol 27 No 12, Dec 91 pp 2653-2654

[Article by A.N. Popkov, V.S. Vekshina, O.V. Nagibin, N.I. Pepik, State Scientific Research and Design Institute of Rare Earth Metals Industry]

UDC 66.046.522

[Abstract] The factors affecting the impurity distribution in the length of growing crystal are outlined and the use of magnetic field in order to manipulate the mass and heat transfer processes during the growth of crystals and control the impurity distribution is discussed. The effect of magnetic field on the effective distribution coeffi-cients of residual germanium and tellurium impurities in an indium antimonide crystal grown in the [211] direc-tion with a transverse magnetic field applied to the melt is investigated in nondoped InSb grown by CzochralskPs method with a magnetic flux density of up to 0.17 T. The dependence of the effective distribution coefficient of tellurium and residual impurities on the magnetic field