Interaction between the components in Tm-Cr-Ge system at 1070 K

The phase equilibrium diagram of the Tm-Cr-Ge ternary system was constructed at a temperature 1070 K based on the results of X-ray phase, microstructural analyzes and energy-dispersive X-ray spectroscopy in the whole concentration range. At the temperature of investigation, two new ternary compounds are realized in the system: TmCr6Ge6 (SmMn6Sn6 structure type, space group P6/mmm, a=0.51506(1), c=0.82645(2) nm) and Tm4Cr4Ge7 (Zr4Co4Ge7 structure type, space group I4/mmm, а=1.39005(9), с=0.54441(1) nm). Inclusion of Cr atoms in the structure of the binary germanide TmGe2 (structure type ZrSi2) up to 10 at. % Cr leads to the formation of a solid solution TmCrxGe2 (x = 0-0.33)

Phase equilibrium diagram of Y-Cu-Sb system at 870 K

The interaction of the components in the Y-Cu-Sb ternary system was investigated using the methods of X-ray phase analysis, microstructure, and energy-dispersive X-ray spectroscopy in the whole concentration range at 870 K. At the temperature of investigation Y-Cu-Sb system is characterized by the formation of three ternary compounds: Y3Cu22Sb9 (Dy3Cu20+xSb11-x structure type, space group F-43m, a=1.6614(3) nm), Y3Cu3Sb4 (Y3Au3Sb4 structure type, space group I-43d, а = 0.95357(5) nm), YCuSb2 (HfCuSi2 structure type, space group P4/nmm, a = 0.42580(1), c = 0.98932(3) nm). The solubility of copper in the binary compound YSb (NaCl structure type) extends up to 8 at. %

Дослідження електронної структури напівпровідникового твердого розчину Zr1-xVxNiSn

The peculiarities of electronic and crystal structures of Zr1-xVxNiSn (x = 0 - 0.10) semiconductive solid solution were investigated. To predict Fermi level εF behavior, band gap εg and electrokinetic characteristics of Zr1-xVxNiSn, the distribution of density of electronic states (DOS) was calculated. The mechanism of simultaneous generation of structural defects of donor and acceptor nature was determined based on the results of calculations of electronic structure and measurement of electrical properties of Zr1-xVxNiSn semiconductive solid solution. It was established that in the band gap of Zr1-xVxNiSn the energy states of the impurity donor εD2 and acceptor εA1 levels (donor-acceptor pairs) appear, which determine the mechanisms of conduction of semiconductor.Досліджено особливості електронної та кристалічної структур напівпровідникового твердого розчину Zr1-xVxNiSn (х = 0 – 0,10). Для прогнозування поведінки рівня Фермі εF, ширини забороненої зони εg та кінетичних характеристик Zr1-xVxNiSn розраховано розподіл густини електронних станів (DOS). За результатами розрахунків електронної структури та вимірювання електротранспортних властивостей напівпровідникового твердого розчину Zr1-xVxNiSn визначено механізм одночасного генерування структурних дефектів донорної та акцепторної природи. Встановлено, що у забороненій зоні      Zr1-xVxNiSn з’являються енергетичні стани домішкових донорної εD2 та акцепторної εA1 зон (донорно-акцепторні пари), які визначають механізми електропровідності напівпровідника

Structural studies and magnetism of Dy6Ni2.43Sn0.5 stannide

Intermetallic compound Dy6Ni2.43Sn0.5 was prepared by arc melting and annealing at 873 K. It was characterized by X-ray powder diffraction, differential thermal analysis, and electron probe microanalysis. The crystal structure of low temperature Dy6Ni2.43Sn0.5 phase belongs to the orthorhombic Ho6Co2Ga structure type (space group Immm, a = 0.93116(1) nm, b = 0.94993(1) nm, c = 0.98947(1) nm). Crystal structure refinements showed the deviation from the ideal 6:2:1 stoichiometry corresponding to the formula Dy6Ni2.43Sn0.5. It exhibits a sequence of magnetic phase transitions; antiferromagnetic ordering sets in at 60 K, while further order-order magnetic phase transitions take place at lower temperatures

Потрійна система Er-Cr-Ge

The isothermal section of the phase diagram of the Er–Cr–Ge ternary system was constructed at 1070 K over the whole concentration range using X-ray diffractometry, metallography and electron microprobe (EPM) analysis. The interaction between the elements in the Er−Cr−Ge system results in the formation of two ternary compounds: ErCr6Ge6 (MgFe6Ge6-type, space group P6/mmm, Pearson symbol hP13; a = 5.15149(3), c = 8.26250(7) Ǻ; RBragg = 0.0493, RF = 0.0574) and ErCr1-хGe2 (CeNiSi2-type, space group Cmcm, Pearson symbol oS16, a = 4.10271(5), b = 15.66525(17), c = 3.99017(4) Ǻ; RBragg = 0.0473, RF = 0.0433) at investigated temperature. For the ErCr1-xGe2 compound, the homogeneity region was determined (ErCr0.28-0.38Ge2; a = 4.10271(5)-4.1418(9), b = 15.6652(1)-15.7581(4), c = 3.99017(4)-3.9291(1) Ǻ).Ізотермічний переріз діаграми стану потрійної системи Er–Cr–Ge побудований за температури 1070 K в повному концентраційному інтервалі методами рентгенофазового, рентгеноструктурного і мікроструктурного аналізів. Взаємодія компонентів у системі Er–Cr–Ge за температури дослідження характеризується утворенням двох тернарних сполук ErCr6Ge6 (структурний тип MgFe6Ge6, просторова група P6/mmm, символ Пірсона hP13; a = 5,15149(3), c = 8,26250(7) Ǻ; RBragg = 0,0493, RF = 0,0574) іErCr1-хGe2 (структурний тип CeNiSi2, просторова група Cmcm, символ Пірсона oS16, a = 4,10271(5), b = 15,6652(1), c = 3,99017(4) Ǻ; RBragg = 0,0473, RF = 0,0433). Для сполуки ErCr1-хGe2 визначена область гомогенності (ErСr0,28-0,38Ge2; a = 4,10271(5)-4,1418(9), b = 15,6652(1)-15,7581(4), c = 3,99017(4)-3,9291(1) Ǻ)

TSFZ Growth of Eu Substituted Large Size LSCO Crystals

The travelling solvent floating zone TSFZ growth of Eu substituted LSCO La1.81 amp; 8722;xEuxSr0.19CuO4, with nominal x 0 0.4 single crystals was systematically explored for the first time. The substitution of La with Eu considerably decreased the decomposition temperature. Optimal growth parameters were found to be oxygen pressure 9.0 9.5 bars; Eu free CuO poor solvent 66 mol CuO with a molar ratio of La2O3 SrCO3 CuO 4 4.5 16.5 and growth rate 0.6 mm hour. The obtained single crystals were characterized with optical polarized microscopy, X ray diffraction and energy dispersive X ray spectroscopy analysis. The solubility of Eu in LSCO appeared to be limited to x 0.36 0.38 under the used conditions. The substitution of La3 with smaller Eu3 ions led to a structural transition from tetragonal with space group I4 mmm for La1.81Sr0.19CuO4 x 0 to orthorhombic with space group Fmmm for La1.81 amp; 8722;xSr0.19EuxCuO4 x 0.2, 0.3, 0.4 , and to a substantial shrinking of the c axis from 13.2446 x 0.0 to 13.1257 x 0.4 . Such structural changes were accompanied by a dramatic decrease in the superconducting critical temperature, Tc, from 29.5 K for x 0 to 13.8 K for 0.2. For x amp; 8805; 0.3, no superconductivity was detected down to 4

Peculiarity of component interaction in Gd-Cu-Sn ternary system at 670 K and 770 K

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Electrical transport properties and electronic structure of RNiSn compounds (R = Y, Gd, Tb, Dy, and Lu)

International audienc

Phase equilibria in the Gd–Cr–Ge system at 1070 K

The isothermal section of the phase diagram of the Gd–Cr–Ge ternary system was constructed at 1070 K over the whole concentration range using X-ray diffractometry, metallography and electron microprobe (EPM) analysis. Three ternary compounds are realized in the Gd–Cr–Ge system at the temperature of annealing: Gd117Cr52Ge112 (Tb117Fe52Ge112 structure type,  space group Fm-3m, Pearson symbol cF1124, a = 2.8971(6) nm), GdCr6Ge6 (SmMn6Sn6 structure type, space group P6/mmm, Pearson symbol hP16, a = 0.51797(2), c = 0.82901(4) nm) and GdCr1-хGe2 (CeNiSi2 structure type, space group Cmcm, Pearson symbol oS16, a = 0.41569(1)-0.41593(8), b = 1.60895(6)-1.60738(3), c = 0.40318(1)-0.40305(8) nm). For the GdCr1-xGe2 compound the homogeneity range was determined (x=0.73 – 0,69)

Modeling of the properties of the semiconductor solid solution Lu1-xVxNiSb in the presence of magnetic ordering; [Моделювання властивостей напівпровідникового твердого розчину Lu1-xVxNiSb за наявності магнітного упорядкування]

Modeling of the thermodynamic, structural, energetic and magnetic properties of the semiconductor solid solution Lu1-xVxNiSb was carried out under the condition of the presence of a magnetic moment on the V atoms and the occurrence of spontaneous magnetization. It is shown that the change in the unit cell parameter a(x) and the mixing enthalpy ΔHmix(х) depends little on the presence or absence of spontaneous magnetization. Modeling of the distribution of the density of electronic states DOS in the presence of a magnetic moment on V atoms revealed the splitting of energy states with spins up and down while preserving the band gap εg of Lu1-xVxNiSb. The relationship between the concentration of magnetic V atoms in Lu1-xVxNiSb and the Curie temperature ТС, when spontaneous magnetization is destroyed and the substance becomes paramagnetic, is established. The solid solution semiconductor Lu1-xVxNiSb, provided spontaneous magnetization is present, can be considered as a promising magnetocaloric