Investigation of the Gd−Fe−Pb, Y−Co−Pb, Sm−Co−Pb and Gd−Co−Pb systems at 870 (670) K.

Рентгенівським методом порошку побудовано ізотермічні перерізи діаграм стану систем Gd−Fe−Pb, Y−Co−Pb, Sm−Co−Pb і Gd−Co−Pb при 870 (670) К. У досліджених системах підтверджено наявність тернарних сполук Y12Co6Pb, Y6Co2,23Pb0,57, Sm12Co6Pb, Gd12Co6Pb і Gd6Co2,37Pb0,56 та виявлено існування нових тернарних сполук Gd5FePb3, R5CoPb3 (R = Y, Sm, Gd) (структурний тип Hf5CuSn3, просторова група P63/mcm). The isothermal sections of the Gd-Fe-Pb, Y-Co-Pb, Sm-Co-Pb and Gd-Co-Pb systems at 870 (670) К were constructed. The existence of the ternary Y12Co6Pb, Y6Co2,23Pb0,57, Sm12Co6Pb, Gd12Co6Pb and Gd6Co2,37Pb0,56 compounds in the investigated systems was confirmed. Additionally the formation of new ternary Gd 5FePb3, R5CoPb3 (R = Y, Sm, Gd) compounds (Hf5CuSn3 structure type, space group P63/mcm) was established

Investigation of the M–Pb–{S, Se, Te} (M = Co, Ni, Cu, Ag)

Ізотермічні перерізи діаграм стану систем M–Pb–{S, Se, Te} (M = Co, Ni, Cu, Ag) побудовано за результатами рентгенофазового аналізу. Підтверджено існування відомих із літератури тернарних сполук Ni3Pb2X2 (X = S, Se) (структ. тип Ni3Ni2S2, прост. група R 3m). Нових тернарних сполук не виявлено. The isothermal sections of the M−Pb−{S, Se, Te} (M = Co, Ni, Cu, Ag) systems have been constructed using X-ray phase analysis. The formation of known from literature ternary Ni3Pb2X2 (X = S, Se) (Ni3Ni2S2 structure type, space group R 3 m) has been confirmed. The formation of new ternary compounds has been not observed

Phase Equilibria in the Sm(Ho)2S3–PbS–SnS2 Systems at 770 K

На основании результатов рентгенофазового анализа исследовано физико-химическое взаимодействие компонентов в квазитройных системах Sm2S3–PbS–SnS2 и Ho2S3–PbS–SnS2. Построены изотермические сече- ния исследуемых систем при температуре 770 К Interaction of the components in the Sm2S3 – PbS – SnS2 and Ho2S3 – PbS – SnS2 systems have been investigated using X-ray phase analysis. Isothermal sections of the investigated systems have been constructed at 770 К

Dy8SnS13.61O0.39 from single-crystal data

Crystals of the title dysprosium tin sulfide oxide, Dy8SnS13S1−xOx [x = 0.39 (4)], were obtained unintentionally from the Dy–Sn–S system. A statistical mixture of sulfur and oxygen was assumed for one position in the structure. S and O atoms surround each of the eight symmetrically non-equivalent dysprosium atoms. The Sn atoms are located in tetra­hedral surroundings of sulfur atoms. Trigonal prisms and tetra­hedra are connected to each other by their edges. All atoms are situated in mirror planes

Investigation of the Dy2S3-Cu2S-SnS2 and Dy2Se3-Cu2Se-SnSe2 Systems at 870 K.

Взаємодія між компонентами в системах Dy2S3–Cu2S–SnS2 та Dy2Se3–Cu2Se–SnSe2 при 870 К досліджена методами рентгенівської порошкової дифрактометрії. За температури відпалу в системах Dy2S3–Cu2S-SnS2 та Dy2Se3–Cu2Se–SnSe2 виявлено існування тетрарних сполук Dy3CuSnX7 (X – S, Se). Взаимодействие между компонентами в системах Dy2S3–Cu2S–SnS2 и Dy2Se3–Cu2Se–SnSe2 при 870 К исследовано методами ренгтгеновской порошочной дифрактометрии. При температуре отпала в системах Dy2S3–Cu2S-SnS2 и Dy2Se3–Cu2Se–SnSe2 выявлено наличие тетраных соединений Dy3CuSnX7 (X – S, Se). The interactions between components in the Dy2S3-Cu2S-SnS2 and Dy2Se3-Cu2Se-SnSe2 systems at 870 К were determined using X-ray powder diffraction. The existence of the compounds with composition Dy 3CuSnX7 (X – S, Se) was confirmed in the Dy2S3–Cu2S–SnS2 and Dy2Se3–Cu2Se–SnSe2 system

Isothermal sections of the systems Y(La)2Sе3–In2Se3–PbSe at 870 K

Взаємодію між компонентами в системах Y(La)2Sе3–In2Se3–PbSe при 870 K досліджено методом рентгенівської порошкової дифрактометрії. В системах не виявлено існування тетрарних сполук. The interactions between the components in the Y2Sе3–In2Se3–PbSe and La2Sе3–In2Se3–PbSe system at 870 К were determined using X-ray powder diffraction. No quaternary compounds exist in the investigated systems

Isothermal Sections of the Sm(Er)2Se3 – PbSe – GeSe2 Systems at 770 K and Crystal Structure of Sm1,32Pb1,68Ge1,67Se7 Compound

За допомогою рентгенофазового аналізу досліджено взаємодію компонентів у квазіпотрійних системах Sm2Se3 – PbSe – GeSe2 і Er2Se3 – PbSe – GeSe2 при температурі 770 К. Встaновлено існування та вивчено методом порошку кристалічну структуру тетрарної сполуки Sm1,32Pb1,68Ge1,67Se7 (пр. гр. P63, а = 1,04569(4) нм, c = 0,66222(5) нм). The interaction has been studied between the components in quasiternary systems Sm2Se3 – PbSe – GeSe2 and Er2Se3 – PbSe – GeSe2 at 770 K using X-ray phase methods. Existence has been found and the crystal structure of Sm1,32Pb1,68Ge1,67Se7 compound has been examined by means of powder diffraction method (space group P63, а = 1,04569(4) nm, c = 0,66222(5) nm)

A new polymorphic material? Structural degeneracy of ZrMn_2

Based on density functional calculations, we propose that ZrMn_2 is a polymorphic material. We predict that at low temperatures the cubic C15, and the hexagonal C14 and C36 structures of the Laves phase compound ZrMn_2 are nearly equally stable within 0.3 kJmol^{-1} or 30 K. This degeneracy occurs when the Mn atoms magnetize spontaneously in a ferromagnetic arrangement forming the states of lowest energy. From the temperature dependent free energies at T approx 160K we predict a transition from the most stable C15 to the C14 structure, which is the experimentally observed structure at elevated temperatures.Comment: 4 pages, 3 figure