Lubomir D. Gulay

Lesya Ukrainka Eastern European National University · Department of Ecology and Protection of Environment

X-ray diffraction and differential-thermal analysis methods were used for investigation of the component interaction in the Cu2S − Ga2S3 – In2S3 system. The existence of the quaternary phase CuGaxIn5-xS8 where 1.4 = x ≤ 2.05 at 820 K was confirmed. The crystal structure of the quaternary phase was determined by X-ray powder method for the CuGa1.6In...

The formation of the La2-xR'xPbSi2S8 (R' = Ce, Pr, Sm, Tb, Dy, Y, Ho, Er), Ce2-xR'xPbSi2S8 (R' = Pr, Sm, Tb, Dy, Y, Ho, Er), and Pr2-xR'xPbSi2S8 (R' = Sm, Tb, Dy, Y, Ho, Er) (x = 1.5, 1.0, 0.5) solid solutions was established. The crystal structures of LaR'PbSi2S8 (R = Ce, Sm, Tb, Dy, Y, Ho, Er), CeR'PbSi2S8 (R' = Pr, Sm, Tb, Dy, Y, Ho, Er) and PrR...

The quasi-ternary systems Er2S3–In2S3–Ga2S3 was investigated by X-ray method, the isothermal section of the system at 770 K was constructed. Using X-ray structure analysis the crystal structures of the new compounds Ga2.78In3.88Y3.35S15 (I), Ga2.98In2.66Er4.37S15 (II), Ga3.37In1.26Tm5.37S15 (III), Ga3.46In1.58Yb4.96S15 (IV) were calculated. They cr...

One of the directions for finding new materials is to complicate the component composition of the compounds. Therefore, the acquisition of new tetrachloride halogens and the study of their crystalline structure have become the object of this search. Ternary and quaternary chalcohenides and chalcоhalohenides with tetrahedral coordination cations are...

Quaternary compounds Er2.34Се(Pr)0.66Ge1.28S7 are formed in the quasi-ternary systems Er2S3–R2S3–GeS2 (R–Ce, Pr) at 770 K. The structure of these compounds was determined from data sets obtained from homogeneous samples weighing 0.8 g recorded at a DRON 4-13 X-ray diffractometer, CuKα radiation, in the range of 10°≤2θ≤100°, scan step 0.05°, 20 s ex...

Isothermal section of the Er2S3–La2S3–GeS2 system at 770 K was investigated. The phase boundaries of the solid solution La4–4xR4xGe3S12 (x = 0–0.75, R – Tb, Dy, Ho and Er) were determined, and their structure was investigated by single crystal and powder X-ray diffraction. The existence of new quaternary compound Er2.34La0.66Ge1.28S7 was establishe...

The isothermal section of the Y2S3–La2S3–GeS2 system at 770 K was investigated. The existence of a solid solution Y4xLa4–4xGe3S12 (x = 0–0.75) was established for the first time. The crystal structure of the Y2La2Ge3S12 compound was studied by X-ray powder method (space group R3c, Pearson symbol hR38, a = 1.92587(9) nm, c = 0.79121(5) nm, RI = 0.08...

The rare-earth chalcogenides have been systematically synthesized for many years owing to their specific thermal, electrical, magnetic, and optical properties. In the silicon, germanium, tin, and lead systems, a simple substitution one element by another could result in a similar structure. However, the structural relationships among the ternary or...

Isothermal sections of the quasi-ternary systems Ag2S(Se)-Ga2S(Se)(3)-In2S(Se)(3) at 820 K were compared. Along the 50 mol% Ag2S(Se), both systems feature continuous solid solutions with the chalcopyrite structure. Along the 17 mol% Ag2S(Se), the interactions at the AgIn5S(Se)(8)-"AgGa5S(Se)(8)" sections are different. In the Ag2S-Ga2S3-In2S3 syste...

The crystal structure of quaternary compounds R3Co0.5GeS7 (R = Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er and Tm) and R3Ni0.5GeS7 (R = Y, Ce, Sm, Gd, Tb, Dy, Ho, Er and Tm) (La3Mn0.5SiS7 structure type, space group P63, Pearson symbol hP23) was determined by means of X-ray single crystal diffraction. The R atoms are located in trigonal prisms with t...

Single crystals of Gd4(SiO4)2OTe are accidentally obtained while studying the Gd2Te3—Cu2Te system using Gd, Cu, and Te in the molar ratio of 1:1:2 (evacuated quartz tubes, 1420 K, 3 h; cooling to 870 K at a rate of 10 K/h).

Designing new functional materials with increasingly complex compositions is of current interest in science and technology. Complex rare-earth-based chalcogenides have specific thermal, electrical, magnetic and optical properties. Tetragadolinium bis[tetraoxidosilicate(IV)] oxide telluride, Gd4(SiO4)2OTe, was obtained accidentally while studying th...

The crystal structure of quaternary compounds R3Fe0.5GeS7 (R = Y, La, Ce, Pr, Sm, Gd, Tb, Dy, Ho, Er and Tm) was determined by means of single-crystal and powder X-ray diffraction methods. It is of the hexagonal La3Mn0.5SiS7 type (space group P63, Pearson symbol hP23) The R atoms occupy trigonal prisms capped with two additional atoms, the Fe atoms...

The title compounds are characterized by powder and single crystal XRD, and magnetic measurements in the temperature range 1.72—400 K in external fields up to 5 T.

The crystal structures of quaternary R3Mn0.5GeS7 (R = Y, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho and Er) compounds of La3Mn0.5SiS7 structure type (space group P63, Pearson symbol hP23) were determined by means of single crystal X-ray diffraction. The R atoms occupy trigonal prisms with two additional atoms, the Mn atoms are located in octahedra, while the G...

The title compounds are prepared from the elements (1150 °C, 3 h, annealing at 500 °C for 720 h) and characterized by single crystal XRD and magnetic measurements.

The quasi-ternary system Cu2Se-Ga2Se3-GeSe2 was investigated using the methods of differential thermal and x-ray analysis. An isothermal section at 770 K and a liquidus surface projection of the phase diagram were constructed. The existence of the quaternary phase CuGaGeSe4, the boundaries of solid solutions ranges of the system compounds were esta...

The crystal structures of new compounds in the title systems are determined by powder XRD.

The title compounds are characterized by powder and single crystal XRD and magnetic measurements.

The crystal structures of the compounds RE2Pt2Pb (RE = Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; Mo2FeB2 structure type, space group P4/mbm, Pearson code tP10), REPtPb (RE = La, Ce, Pr, Nd, Sm; ZrNiAl structure type, space group P (6) over bar 2m, Pearson code hP9), RE2Au2Pb (RE = Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb an...

The crystal structures of the title compounds are reinvestigated by single crystal XRD.

The title compounds are prepared from the elements (1150 °C for 3 h followed by annealing at 500 °C for 720 h) and their crystal structure is determined by powder and single crystal XRD.

The crystal structures of several novel quaternary compounds R2PbSi2S8 (R = Y, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho), R2PbSi2Se8 (R = La, Ce, Pr, Nd, Sm, Gd) and R2PbGe2S8 (R = Ce, Pr) have been determined by means of single-crystal and powder X-ray diffraction. All these phases crystallize with hexagonal unit cells of the La2PbSi2S8 type (space group R-...

The crystal structure of the R6Si4Se17 (R = La and Ce) selenides was studied by means of X-ray powder and single crystal diffraction. The magnetic behaviour of the Ce-based compound was determined through SQUID magnetometry. The two materials crystallize with the Ce6Si4S17 structure type (space group P1¯, Pearson symbol aP54). Their unit cells comp...

The crystal structures of ternary compounds TbCu{sub 3}S{sub 3}, Dy{sub 1.06}Cu{sub 2.84}S{sub 3} (space group R3-bar), Ho{sub 0.67}Cu{sub 2}S{sub 2} (space group P3-bar m1), ErCu{sub 3}S{sub 3} (space group P3-bar 1c), Yb{sub 0.80}Cu{sub 1.60}S{sub 2}, Lu{sub 0.67}Cu{sub 2}S{sub 2}, TbCuTe{sub 2}, DyCuTe{sub 2}, Tm{sub 1.07}Cu{sub 0.78}Te{sub 2},...

The compounds with the general formula Ln3MTX7 (space group P63) (Ln – rare-earth element, M – monovalent element (Cu, Ag), T – Si, Ge, Sn and X – S, Se) are interesting owing to the possible application in the field of ionic conductivity. In the crystal structure the face-sharing [Ag(S)6] triangular antiprisms form the channels where the Ag+ ion c...

The rare earth chalcogenides have been systematically synthesized for many years owing to their specific thermal, electrical, magnetic, and optical properties. In the silicon, germanium, tin, lead, and indium systems, a simple substitution one element by another could result in a similar structure. However, the structural relationships among the te...

The crystal structure of distrontium octacyanotungstate decahydrate, Sr2[W(CN)8]·10H2O, was solved using X-ray single crystal diffraction. The tungsten atom lies on a two fold axis. Eight cyanide anions create tetragonal antiprismatic coordination sphere of tungsten atom. The two edge-sharing tetragonal antiprisms of [Sr(NC)3(OH2)5], create a dimer...

The crystal structure of distrontium octacyanotungstate decahydrate, Sr 2[W(CN) 8]·10H 2O, was solved using X-ray single crystal diffraction. The tungsten atom lies on a two fold axis. Eight cyanide anions create tetragonal antiprismatic coordination sphere of tungsten atom. The two edge-sharing tetragonal antiprisms of [Sr(NC) 3(OH 2) 5], create a...

Single crystals of the title compound are obtained from a melt of the elements (evacuated silica tube, 1420 K, 3 h).

The crystal structure of copper(I) lanthanum selenide, La(3)Cu(4.88)Se(7), obtained from the La(2)Se(3)-Cu(2)Se quasi-binary system, has been investigated using X-ray single-crystal diffraction. The positions of the La and Se atoms are ordered and lie on mirror planes, whereas all positions for the Cu atoms are partially occupied. The crystal is bu...

La3Ge1.48Se7, Ce3Ge1.47Se7, Pr3Ge1.49Se7, Sm3Ge1.48Se7, Gd3Ge1.45Se7, and Tb3Ge1.43Se7 crystallize with the Dy3Ge1.25S7 type structure in the space group P63 with Z = 2 (single crystal XRD).

The crystal structures of the Ag2.66Hg2Sn1.34Se6 and Hg2SnSe4 compounds were investigated using X-ray powder diffraction. The Ag2.66Hg2Sn1.34Se6 compound crystallizes in an orthorhombic unit cell (space group Imm2, a=1.2795(2), b=0.42631(6), c=0.58207(4) nm). The Hg2SnSe4 compound crystallizes in the thiogallate structure (defect chalcopyrite) (spa...

The crystal structures of ternary compounds R3Ge1+xSe7 (Dy3Ge1.25S7 structure type, space group P63, Pearson symbol hP22 + 2x, a = 10.7656(7) Å, с = 6.0801(5) Å, R1 = 0.0186 for La3Ge1.48Se7; a = 10.684(1) Å, с = 6.0611(8) Å, R1 = 0.0257 for Ce3Ge1.47Se7; a = 10.6408(9) Å, с = 6.0548(7) Å, R1 = 0.0290 for Pr3Ge1.49Se7; a = 10.4419(7) Å, с = 6.0283(...

Single crystals of a new monoclinic modification of Cu2Se3Sn are obtained from the elements at 1380 K (evacuated silica tube, 2 h).

The crystal structures of novel quaternary compounds Sm3CuGeS7 and Sm3CuGeSe7 were determined by means of X-ray single crystal diffraction. They are of the La3CuSiS7 structure type, space group P63, Pearson symbol hP24. The refined lattice parameters are a = 10.0106(7) Å, с = 5.7702(6) Å for Sm3CuGeS7, and a = 10.4091(9) Å, с = 6.0382(6) Å for Sm3C...

The crystal structures of the Cu6Hg0.973SiS5.973 and Ag6Hg0.897SiS5.897 compounds were investigated using X-ray powder diffraction. These compounds are isostructural with Ag6Hg0.82GeS5.82 (space group P213, a=1.05547 nm). Lattice parameters are: a=0.98938(1) nm for Cu6Hg0.973SiS5.973 and a=1.05055(2) nm for Ag6Hg0.897SiS5.897. Atomic parameters wer...

A previously unknown modification of dicopper(I) triselenostannate(IV), Cu(2)Se(3)Sn, has been obtained from the Cu(2)Se-SnSe(2) quasi-binary system and investigated using X-ray single-crystal diffraction. The Se atoms are stacked in a closest-packed arrangement with the layers in the sequence ABC. The Cu atoms occupy one-third of the tetrahedral i...

Crystals of La(2)Pb(SiS(4))(2), dilanthanum(III) lead(II) bis[tetrasulfidosilicate(IV)], were obtained from the La-Pb-Si-S system and structurally characterized using X-ray single-crystal diffraction. The La and Pb atoms are coordinated in bicapped trigonal prisms of S atoms, with the Si atoms in tetrahedra. An occupational disorder of the La and P...

Lanthanum phosphite microspheres with diameters of 80–100 μm were obtained under hydrothermal conditions by using lanthanum oxalate as precursor. The surfaces of these spherules consist of well-orientated submicron-sized rods with typical diameters of 300 nm and lengths of 6 μm. The possible mechanism of formation of this morphology was suggested....

The crystal structures of the Ln3Ag(1-delta)GeS7 (Ln = La-Nd, Sm, Gd-Er, Y; delta = 0.11-0.50, space group P6(3)) compounds were determined by means of X-ray single-crystal diffraction and the similarities among the crystal structures of all Ln3M(1-delta)TX7 (space group P6(3); Ln--lanthanide element, M--monovalent element; T--tetravalent element a...

Single crystal of Ce2RhSi3 was investigated by means of x-ray diffraction, magnetization, electrical resistivity, and heat-capacity measurements. Moreover, its electronic structure was studied by cerium core-level x-ray photoemission spectroscopy. The results revealed that Ce2RhSi3 is an antiferromagnetic Kondo lattice due to the presence of stable...

The crystal structures of the R3Ag1−δGeSe7 (R=La–Nd, Sm, Gd–Dy, δ=0.06–0.28) and R3Ag1−δSiSe7 (R=La–Nd, Sm, Gd–Dy, δ=0–0.30) compounds were determined by means of X-ray single crystal diffraction (space group P63): a=1.0806(1)nm, c=0.6111(1)nm, R1=0.0280 for La3Ag0.94GeSe7; a=1.0711(1)nm, c=0.60719(5)nm, R1=0.0126 for Ce3Ag0.89GeSe7; a=1.0619(1)nm,...

High-quality single crystal of Ce2RhSi3 was studied by means of thermoelectric power measurements carried out down to 2 K in external magnetic fields up to 13 T. The results obtained above 50 K were interpreted in terms of a modfied two-band model that takes into account temperature variation of the width of 4f-derived narrow band located near the...

The orthorhombic crystal structures of the series of Ln4−xIn5−yS13 (Ln=La, Ce, Pr and Nd; x=0.08–0.12, y=0.21–0.24) compounds were investigated by means of X-ray crystal diffraction. The crystals of La3In1.67S7 and Gd3InS6 were also obtained unexpectedly from the La–In–S and Gd–In–S systems and no respective Gd4−xIn5−yS13 was obtained. In the struc...

The crystal structure of the RE2PbS4 (RE = Y, Dy, Ho, Er and Tm) compounds (space group Cmc21, Pearson symbol oC112, a = 0.79301(3) nm, b = 2.86966(9) nm, c = 1.20511(5) nm, RBragg = 0.0979 for Y2PbS4; a = 0.79484(8) nm, b = 2.8721(3) nm, c = 1.2039(1) nm, for Dy2PbS4; a = 0.79081(2) nm, b = 2.86222(7) nm, c = 1.20220(4) nm, RBragg = 0.0859 for Ho2...

The new intermetallic cerium compound CeRhPb was synthesized by arc melting and studied by means of X-ray diffraction and magnetic measurements. The crystal structure determined from the single-crystal X-ray data is of the ZrNiAl type (space group P (6) over bar 2m). The compound was found to be a Pauli paramagnet with 4f(0) ground state of the Ce...

The crystal structure of the R3Ag1−δSiS7 (R=La, Ce, Pr, Nd, Sm, δ=0.10–0.23, space group P63, Pearson symbol hP23.80−23.54) compounds were determined by means of X-ray single crystal diffraction (a=1.04168(8)nm, c=0.57825(4)nm, R1=0.0116 for La3Ag0.90SiS7; a=1.0312(1)nm, c=0.57395(7)nm, R1=0.0152 for Ce3Ag0.82SiS7; a=1.0248(1)nm, c=0.57223(5)nm, R1...

The crystal structure of low temperature modification of LuNiPb was determined by using X-ray powder diffraction (ZrNiAl structure type, space group P6¯2m, Pearson code hP9, a = 0.74084(1) nm, c = 0.37607(1) nm, RI = 0.0540). The Lu atoms are surrounded by pentagonal prisms with seven additional atoms, the Ni atoms by trigonal prisms with three add...

The crystal structure of new ternary R3Si1.25Se7 (R = Pr, Nd and Sm) compounds (Dy3Ge1.25S7 structure type, Pearson symbol hP22.5, space group P63, a = 1.05268 (3) nm, c = 0.60396 (3) nm, RI = 0.0897 for Pr3Si1.25Se7; a = 1.04760 (3) nm, c = 0.60268 (3) nm, RI = 0.0891 for Nd3Si1.25Se7; a = 1.04166 (6) nm, c = 0.59828 (6) nm for Sm3Si1.25Se7) was d...

The crystal structures of the R2Pb3Sn3S12 (R = La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er and Tm) compounds (space group Pmc21, Pearson symbol oP40, a = 0.38992 (1) nm, b = 2.01175 (7) nm, c = 1.15140 (4) nm, RI = 0.0785 for Ho2Pb3Sn3S12) were investigated using X-ray powder diffraction. The R1 atoms are surrounded by trigonal prisms with two additiona...

LnCuSe2 compounds crystallize either in the monoclinic LaCuS2 (space group P21/c) or the trigonal CaLi2Si2 (space group ) type of structure. The first group is formed by the light rare-earth elements (Ln = La, Ce, Pr, Nd, Sm, Gd and Tb), the second by the heavier rare-earth elements (Ln = Tb, Dy, Ho, Er, Tm, Yb, Lu). Accordingly, the formation of t...

The interactions between the components in the R2Te3–M2Te–PbTe (R = Tb, Dy; M = Cu, Ag) systems at 770 K were determined using X-ray powder diffraction. The formation of the compounds R7Cu3Te12 (Ho7Cu3Te12 structure type, space group R3¯m), RCu5Te4 (unknown structure), RAgTe2 (ErAgTe2 structure type, space group P4¯21m) and the solid solutions R(2+...

Phase equilibria in the Sc2Se3-Cu2Se- SnSe2 and Sc2Se3-Cu2Se-PbSe systems at 870 K were determined using X-ray powder diffraction. The crystal structure of the ScCuSe2 (space group C2/m, a = 1.2762(3) nm, b = 0.7752(1) nm, c = 0.9260(1) nm, β = 133.32(2)°, R1 = 0.0396, wR2 = 0.1141 ) of the Sc2Se3-Cu2Se section was reinvestigated using X-ray single...

Phase equilibria in the Sc(2)Se(3)-Cu(2)Se-SnSe(2) and Sc(2)Se(3)-Cu(2)Se-PbSe systems at 870 K were determined using X-ray powder diffraction. The crystal structure of the ScCuSe(2) (space group C2/m, a = 1.2762(3) nm, b = 0.7752(1) nm, c = 0.9260(1) nm, (3 = 133.32(2)degrees, R1 = 0.0396, wR2 = 0.1141) of the Sc(2)Se(3)-Cu(2)Se section was reinve...

The crystal structure of the R(2)SnS(5) (R = Pr, Nd, Gd and Tb) compounds has been investigated using X-ray single-crystal diffraction. Crystal architecture and structural relationships among U(3)S(5), Y(2)HfS(5), R(2)SnS(5) compounds are discussed and a structural origin is determined. It is shown that the complex architecture of the crystal struc...

The crystal structure of the R2PbS4 (R=Yb and Lu) compounds (space group Pnma, Pearson symbol oP28, a=1.1899(2)nm, b=0.39015(8)nm, c=1.4127(2)nm, R1=0.0349 for Yb2PbS4 and a=1.1919(2)nm, b=0.38890(8)nm, c=1.4103(3)nm, R1=0.0343 for Lu2PbS4) was investigated by means of X-ray single crystal diffraction. The R atoms are surrounded by octahedra, the P...

The crystal structure of the R6Si4S17 compounds (R = Pr, Nd and Sm) (Ce6Si4S17 structure type, space group P1¯, Pearson symbol aP54) was determined by means of X-ray single crystal diffraction (a = 0.8902(1) nm, b = 0.9934(1) nm, c = 1.4206(2) nm, α = 82.19(1)°, β = 86.94(1)°, γ = 89.40(1)°, R1 = 0.0389 for Pr6Si4S17; a = 0.8880(1) nm, b = 0.9903(1...