Dimorphic EuCu5Cd

2012 ◽  
Vol 67 (10) ◽  
pp. 1107-1114 ◽  
Author(s):  
Frank Tappe ◽  
Christian Schwickert ◽  
Rainer Pöttgen
Keyword(s):  
Magnetic Susceptibility ◽  
Small Degree ◽  
Muffle Furnace ◽  
Temperature Dependent ◽  
X Ray ◽  
Coordination Numbers ◽  
Dsc Measurements ◽  
Divalent Europium ◽  
Experimental Magnetic Moment ◽  
High Coordination

Two modifications of EuCu5Cd were synthesized from the elements in sealed tantalum ampoules.The high-temperature (HT) modification was obtained from an induction-melted sample that was finally annealed at 873 K, while the low-temperature (LT) phase is formed in a muffle furnace by annealing a pre-melted sample at 673 K. DSC measurements gave a transition temperature of 823±2 K. Both structures were refined on the basis of single-crystal X-ray diffractometer data: R3̄m, a = 511:58(7), c = 3059:6(6) pm, wR2 = 0.0289, 316 F2 values, 22 variables for HTEuCu4 :85(1)Cd1:15(1) and Pnma, a = 2545:6(5), b = 511:60(1), c = 1060:3(2) pm, wR2 = 0.0386, 2044 F2 values, 121 variables for LT-EuCu4:92(1)Cd1:08(1). A small degree of Cu/Cd mixing was observed for three sites. Both structures adopt new types. The europium atoms have high coordination numbers of 18, 19 and 20 in LT- and 18 and 20 in HT- EuCu5Cd. These three types of polyhedra are the basic building units also in the closely related structures of CeCu6, CeCu5Au, CeCu4:38In1:62, and CeNi5Sn, a family of stacking variants. Temperature-dependent magnetic susceptibility measurements of a HT- EuCu5Cd sample showed an experimental magnetic moment of 7.56(1) μB per Eu atom in the paramagnetic regime, compatible with divalent europium. HT- EuCu5Cd orders antiferromagnetically at 17.7(5) K.

Antiferromagnetic ordering in the plumbide EuPdPb

2017 ◽  
Vol 72 (12) ◽  
pp. 989-994
Author(s):  
Lukas Heletta ◽  
Steffen Klenner ◽  
Theresa Block ◽  
Rainer Pöttgen
Keyword(s):  
Magnetic Susceptibility ◽  
Magnetic Hyperfine Field ◽  
Metamagnetic Transition ◽  
Muffle Furnace ◽  
Temperature Dependent ◽  
X Ray ◽  
Antiferromagnetic Ordering ◽  
Divalent Europium ◽  
Polycrystalline Form ◽  
Experimental Magnetic Moment

AbstractThe plumbide EuPdPb was synthesized in polycrystalline form by reaction of the elements in a sealed niobium ampoule in a muffle furnace. The structure was refined from single-crystal X-ray diffractometer data: TiNiSi type, Pnma, a=752.4(2), b=476.0(2), c=826.8(2) pm, wR2=0.0485, 704 F2 values and 20 variables. The europium atoms are coordinated by two tilted and puckered Pd3Pb3 hexagons (280–289 pm Pd–Pb) with pronounced Eu–Pd bonding (312–339 pm). Temperature-dependent magnetic susceptibility measurements show Curie-Weiss behaviour and an experimental magnetic moment of 7.35(1) μB per Eu atom. EuPdPb orders antiferromagnetically at TN=13.8(5) K and shows a metamagnetic transition at a critical field of 15 kOe. 151Eu Mössbauer spectra confirm divalent europium (δ=–10.04(1) mm s−1) and show full magnetic hyperfine field splitting (Bhf=21.1(1) T) at 6 K.

GdCuMg with ZrNiAl-type structure – an 82.2 K ferromagnet

2017 ◽  
Vol 72 (7) ◽  
pp. 511-515 ◽  
Author(s):  
Sebastian Stein ◽  
Lukas Heletta ◽  
Rainer Pöttgen
Keyword(s):  
Magnetic Susceptibility ◽  
Single Crystal ◽  
Magnetic Moment ◽  
Type Structure ◽  
Induction Melting ◽  
X Ray Diffraction ◽  
Muffle Furnace ◽  
Temperature Dependent ◽  
X Ray ◽  
Experimental Magnetic Moment

AbstractGdCuMg has been synthesized by induction-melting of the elements in a sealed niobium ampoule followed by annealing in a muffle furnace. The sample was studied by powder and single crystal X-ray diffraction: ZrNiAl type, P6̅2m (a=749.2(4), c=403.3(1) pm), wR2=0.0242, 315 F2 values and 15 variables. Temperature dependent magnetic susceptibility measurements have revealed an experimental magnetic moment of 8.54(1) μB per Gd atom. GdCuMg orders ferromagnetically below TC=82.2(5) K and based on the magnetization isotherms it can be classified as a soft ferromagnet.

Magnesium-rich Intermetallics RE3RuMg7 (RE=Y, Nd, Dy, Ho) – Rows of Condensed Ru@RE6/2 Octahedra in Magnesium Matrices

2013 ◽  
Vol 68 (12) ◽  
pp. 1273-1278 ◽  
Author(s):  
Marcel Kersting ◽  
Ute Ch. Rodewald ◽  
Christian Schwickert ◽  
Rainer Pöttgen
Keyword(s):  
Magnetic Susceptibility ◽  
Magnetic Moment ◽  
Small Degree ◽  
Intermetallic Phases ◽  
Metamagnetic Transition ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Antiferromagnetic Ordering ◽  
Experimental Magnetic Moment

The magnesium-rich intermetallic phases RE3RuMg7 (RE=Y, Nd, Dy, Ho) have been synthesized from the elements in sealed niobium ampoules and subsequently characterized by powder X-ray diffraction. The structure of the dysprosium compound was refined on the basis of single-crystal X-ray diffractometer data: Ti6Sn5 type, P63=mmc, a=1019.1(2), c=606.76(9) pm, wR2=0.0159, 439 F2 values, 19 variables. The Mg3 site shows a small degree of Mg3=Dy mixing, leading to the composition Dy3:03RuMg6:97 for the investigated crystal. The striking structural motifs in the Dy3RuMg7 structure are rows of face-sharing Ru@Dy6 octahedra and corner-sharing Mg2@Mg8Dy4 icosahedra. The rows of octahedra form a hexagonal rod-packing, and each rod is enrolled by six rows of the condensed icosahedra. Temperature-dependent magnetic susceptibility measurements of Dy3RuMg7 show Curie-Weiss behavior with an experimental magnetic moment of 10.66(1) µB per Dy atom. Antiferromagnetic ordering is detected at TN =27.5(5) K. The 5 K isotherm shows a metamagnetic transition at a critical field of HC =40 kOe

The ternary platinides CaGa5Pt3 and EuGa5Pt3

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Judith Bönnighausen ◽  
Stefan Seidel ◽  
Steffen Klenner ◽  
Rainer Pöttgen
Keyword(s):  
Induction Furnace ◽  
Three Dimensional ◽  
Covalent Bonding ◽  
Intermetallic Phases ◽  
Temperature Dependent ◽  
X Ray ◽  
Antiferromagnetic Ordering ◽  
Divalent Europium ◽  
Experimental Magnetic Moment ◽  
Magnetic Hyperfine Splitting

Abstract The ternary platinides CaGa5Pt3 (a = 2082.5(4), b = 406.05(8), c = 739.2(1) pm) and EuGa5Pt3 (a = 2085.5(5), b = 412.75(9), c = 738.7(1) pm) were synthesized from the elements in sealed high-melting metal tubes in an induction furnace. CaGa5Pt3 and EuGa5Pt3 are isotypic with CeAl5Pt3 and isopointal with the YNi5Si3 type intermetallic phases (space group Pnma, oP36 and Wyckoff sequence c 9). The structure of EuGa5Pt3 was refined from single crystal X-ray diffractometer data: wR2 = 0.0443, 1063 F 2 values and 56 variables. The gallium and platinum atoms build up a three-dimensional [Ga5Pt3]2− polyanionic network in which the europium atoms fill slightly distorted hexagonal prismatic voids. The Ga–Pt distances within the network range from 249 to 271 pm, emphasizing the covalent bonding character. Temperature dependent magnetic susceptibility measurements indicate diamagnetism for CaGa5Pt3 and isotypic BaGa5Pt3. EuGa5Pt3 behaves like a Curie–Weiss paramagnet above 50 K with an experimental magnetic moment of 8.17(1) µB/Eu atom, indicating divalent europium. Antiferromagnetic ordering sets in at T N = 8.5(1) K. The divalent ground state of europium is confirmed by 151Eu Mössbauer spectroscopy. EuGa5Pt3 shows a single signal at 78 K with an isomer shift of −9.89(4) mm s−1. Full magnetic hyperfine splitting with a hyperfine field of 25.0(2) T is observed at 6 K in the magnetically ordered regime.

Intermetallic Cadmium Compounds M5T2Cd (M = Ca, Yb, Eu; T = Cu, Ag, Au) with Mo5B2Si-type Structure

2011 ◽  
Vol 66 (12) ◽  
pp. 1219-1224
Author(s):  
Frank Tappe ◽  
Christian Schwickert ◽  
Matthias Eul ◽  
Rainer Pöttgen
Keyword(s):  
Magnetic Moments ◽  
Small Degree ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Antiferromagnetic Ordering ◽  
Pauli Paramagnetism ◽  
Slab Temperature ◽  
Experimental Magnetic Moment ◽  
The Eu

The intermetallic compounds M5T2Cd (M = Ca, Yb, Eu; T = Cu, Ag, Au) and Yb5Cu2Zn were synthesized by melting the elements in sealed tantalum tubes followed by annealing at 923 K. All phases were characterized on the basis of powder and single-crystal X-ray diffraction data: Mo5B2Si type, I4/mcm, Z = 4, a = 828.7(1), c = 1528.1(3) pm, wR2 = 0.030, 440 F2 values, 16 variables for Eu5Cu2Cd, a = 788.2(1), c = 1459.3(5) pm, wR2 = 0.053, 378 F2 values, 16 variables for Yb5Cu2Cd, and a = 797.2(1), c = 1438.8(3) pm, wR2 = 0.036, 386 F2 values, 17 variables for Yb5Au2.19Cd0.81, which shows a small degree of Au / Cd mixing. The M5T2Cd structures are intergrowth variants of slightly distorted CuAl2- and U3Si2-related slabs. Striking coordination motifs (exemplary for Eu5Cu2Cd) are square antiprisms of the Eu atoms around Cd, Eu8 square prisms around Eu, and trigonal Eu6 prisms around Cu within the AlB2-related slab. Temperature-dependent magnetic susceptibility measurements showed Pauli paramagnetism for Yb5Cu2Zn, indicating purely divalent ytterbium. Eu5Au2Cd exhibits Curie-Weiss behavior above 100 K with an experimental magnetic moment of 8.14 μB per Eu atom and a Weiss constant of 56 K. Antiferromagnetic ordering of the EuII magnetic moments is evident at 36 K, and a metamagnetic transition is observed at 25 K and 13 kOe.

On the Magnetic and Mössbauer Spectroscopic Characterization of EuPd2Sb2

2010 ◽  
Vol 65 (1) ◽  
pp. 18-22 ◽  
Author(s):  
Inga Schellenberg ◽  
Matthias Eul ◽  
Rainer Pöttgen
Keyword(s):  
Magnetic Susceptibility ◽  
Hyperfine Field ◽  
Magnetic Moment ◽  
Spectroscopic Characterization ◽  
Induction Melting ◽  
Temperature Dependent ◽  
Field Splitting ◽  
Divalent Europium ◽  
Experimental Magnetic Moment

The CaBe2Ge2-type antimonide EuPd2Sb2 (P4/nmm, a = 462.43(7), c = 1056.1(2) pm) was synthesized by induction melting of the elements in a sealed tantalum tube. Temperature-dependent magnetic susceptibility measurements have revealed Curie-Weiss behavior with an experimental magnetic moment of 7.93(1) μB/Eu atom, indicating stable divalent europium. EuPd2Sb2 orders antiferromagnetically at TN = 4.5(2) K as is also evident from almost full hyperfine field splitting (Bh = 19.5 T) in the 151Eu Mössbauer spectrum at 4.2 K

Ternary aurides RE4Mg3Au10 (RE = La, Ce, Pr) and RE4Cd3Au10 (RE = Y, La–Nd, Sm, Gd–Dy) – ordering variants of the Zr7Ni10 type

2015 ◽  
Vol 70 (12) ◽  
pp. 889-896 ◽  
Author(s):  
Michael Johnscher ◽  
Theresa Block ◽  
Oliver Niehaus ◽  
Rainer Pöttgen
Keyword(s):  
Magnetic Susceptibility ◽  
Specific Heat ◽  
Coordination Number ◽  
High Frequency ◽  
Two Dimensional ◽  
Muffle Furnace ◽  
Temperature Dependent ◽  
X Ray ◽  
Antiferromagnetic Ordering ◽  
Gold Compounds

AbstractThe intermetallic gold compounds RE4Mg3Au10 (RE = La, Ce, Pr) and RE4Cd3Au10 (RE = Y, La–Nd, Sm, Gd–Dy) were obtained from the elements through high-frequency melting in sealed niobium tubes and subsequent annealing in a muffle furnace. The new aurides crystallize with the Ca4In3Au10-type structure. They were characterized through Guinier powder patterns. The structures of Pr4.46Cd2.54Au10 and Tb4.38Cd2.62Au10 were refined from single crystal X-ray diffractometer data: Cmce, a = 1396.73(6), b = 1009.38(3), c = 1019.51(3) pm, wR2 = 0.0423, 1281 F2 values, 47 variables for Pr4.46Cd2.54Au10 and a = 1362.68(3), b = 995.52(4), c = 1003.79(3) pm, wR2 = 0.0381, 1594 F2 values, F2 47 variables for Tb4.38Cd2.62Au10. The 8e sites of both crystals show substantial Cd/Pr respectively Cd/Tb mixing, indicating small homogeneity ranges for all RE4+xMg3–xAu10 and RE4+xCd3–xAu10 aurides. The gold atoms in these aurides form a pronounced two-dimensional substructure (275–327 pm Au–Au in Pr4.46Cd2.54Au10) which encages the Mg1/Cd1 (coordination number 8) and RE2 (coordination number 11) atoms. These blocks are separated by the Mg2/Cd2 and RE1 atoms with an intergrowth of Mg2/Cd2@Au8 and RE1@Au10 polyhedra. Temperature dependent magnetic susceptibility and specific heat measurements of Tb4Cd3Au10 have shown antiferromagnetic ordering at a Néel temperature of 12(1) K.

Ternary Antimonides RE4T7Sb6 (RE=Gd–Lu; T =Ru, Rh) with Cubic U4Re7Si6-type Structure

2013 ◽  
Vol 68 (9) ◽  
pp. 971-978 ◽  
Author(s):  
Inga Schellenberg ◽  
Ute Ch. Rodewald ◽  
Christian Schwickert ◽  
Matthias Eul ◽  
Rainer Pöttgen
Keyword(s):  
Magnetic Susceptibility ◽  
Single Crystal ◽  
Magnetic Moment ◽  
Induction Furnace ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Antiferromagnetic Ordering ◽  
Arc Melting ◽  
Intermediate Valent

The ternary antimonides RE4T7Sb6 (RE=Gd-Lu; T =Ru, Rh) have been synthesized from the elements by arc-melting and subsequent annealing in an induction furnace. The samples have been characterized by powder X-ray diffraction. Four structures were refined on the basis of single-crystal X-ray diffractometer data: U4Re7Si6 type, space group Im3m with a=862.9(2) pm, wR2=0.0296, 163 F2 values for Er4Ru7Sb6; a=864.1(1) pm, wR2=0.1423, 153 F2 values for Yb4Ru7Sb6; a=872.0(2) pm, wR2=0.0427, 172 F2 values for Tb4Rh7Sb6; and a=868.0(2) pm, wR2=0.0529, 154 F2 values for Er4Rh7Sb6, with 10 variables per refinement. The structures have T1@Sb6 octahedra and slightly distorted RE@T26Sb6 cuboctahedra as building units. The distorted cuboctahedra are condensed via all trapezoidal faces, and this network leaves octahedral voids for the T1 atoms. The ruthenium-based series of compounds was studied by temperature-dependent magnetic susceptibility measurements. Lu4Ru7Sb6 is Pauli-paramagnetic. The antimonides RE4Ru7Sb6 with RE=Dy, Ho, Er, and Tm show Curie-Weiss paramagnetism. Antiferromagnetic ordering occurs at 10.0(5), 5.1(5) and 4.0(5) K for Dy4Ru7Sb6, Ho4Ru7Sb6 and Er4Ru7Sb6, respectively, while Tm4Ru7Sb6 remains paramagnetic. Yb4Ru7Sb6 is an intermediate-valent compound with a reduced magnetic moment of 3.71(1) μB per Yb as compared to 4.54 μB for a free Yb3+ ion

Synthesis, Structure, and Characterization of La1−xBax (0 ≤ x ≤ 1)

1992 ◽  
Vol 271 ◽  
Author(s):  
Joseph E. Sunstrom ◽  
Susan M. Kauzlarich
Keyword(s):  
Magnetic Susceptibility ◽  
Powder Diffraction ◽  
Single Phase ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Temperature Dependent ◽  
X Ray ◽  
Early Transition Metal ◽  
Arc Melting

ABSTRACTThe compounds La1−xBaxTiO3 (0 ≤ × ≤ 1) have been prepared by arc melting stoichiometric amounts of LaTiO3 and BaTiO3. Single phase samples can be made for the entire stoichiometry range. The polycrystalline samples have been characterized by thermal gravimetric analysis, X-ray powder diffraction, and temperature dependent magnetic susceptibility. This series of compounds has been studied as a possible candidate for an early transition metal superconductor.

scholarly journals Borate melt structure: Temperature‐dependent B–O bond lengths and coordination numbers from high‐energy X‐ray diffraction

2018 ◽  
Vol 101 (8) ◽  
pp. 3357-3371 ◽  
Author(s):  
Oliver L. G. Alderman ◽  
Chris J. Benmore ◽  
Alex Lin ◽  
Anthony Tamalonis ◽  
J. K. Richard Weber
Keyword(s):  
High Energy ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Melt Structure ◽  
X Ray ◽  
Coordination Numbers ◽  
Bond Lengths
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