Zn4 tetrahedra as basic building units in intermediate-valent Ce23Ru7Zn4

2015 ◽  
Vol 46 ◽  
pp. 95-101 ◽  
Author(s):  
Oliver Niehaus ◽  
Timo Bartsch ◽  
Rainer Pöttgen
Keyword(s):  
Intermediate Valent

MAGNETIC ORDER IN THE Yb INTERMEDIATE VALENT SYSTEM R0.14Yb0.36In0.5Cu2 (R = Eu, Gd)

1988 ◽  
Vol 49 (C8) ◽  
pp. C8-733-C8-734 ◽  
Author(s):  
I. Felner ◽  
I. Nowik ◽  
Y. Yeshurun
Keyword(s):  
Magnetic Order ◽  
Intermediate Valent

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

Thermal expansion and specific heat of intermediate valent YbCuAl

1981 ◽  
Vol 44 (1-2) ◽  
pp. 17-24 ◽  
Author(s):  
R. Pott ◽  
R. Schefzyk ◽  
D. Wohlleben ◽  
A. Junod
Keyword(s):  
Thermal Expansion ◽  
Specific Heat ◽  
Intermediate Valent

Exciton condensation in intermediate valent Sm0.90La0.10S

2006 ◽  
Vol 359 (5) ◽  
pp. 528-533 ◽  
Author(s):  
P. Wachter ◽  
A. Jung ◽  
F. Pfuner
Keyword(s):  
Exciton Condensation ◽  
Intermediate Valent

Intermediate-valent Ce23Ru7Mg4 and RE23Ru7Mg4 (RE = La, Pr, Nd) with Pr23Ir7Mg4-type Structure

2009 ◽  
Vol 64 (11-12) ◽  
pp. 1345-1352 ◽  
Author(s):  
Stefan Linsinger ◽  
Matthias Eul ◽  
Wilfried Hermes ◽  
Rolf-Dieter Hoffmann ◽  
Rainer Pöttgen
Keyword(s):  
Magnetic Susceptibility ◽  
Rare Earth ◽  
Single Crystal ◽  
Magnetic Moment ◽  
Induction Furnace ◽  
Type Structure ◽  
Space Group ◽  
Structure Space ◽  
Magnesium Compounds ◽  
Intermediate Valent

The rare earth-rich magnesium compounds RE23Ru7Mg4 (RE = La, Ce, Pr, Nd) were synthesized from the elements in sealed tantalum ampoules in an induction furnace. They crystallize with the hexagonal non-centrosymmetric Pr23Ir7Mg4-type structure, space group P63mc. The structures of La23Ru6.88(1)Mg4 (a = 1017.7(4), c = 2286.5(5) pm, wR2 = 0.0277, 2708 F2, 71 variables), Ce23Ru7Mg4 (a = 993.5(3), c = 2243.9(8) pm, wR2 = 0.0573, 2268 F2, 70 variables), and Pr23Ru7Mg4 (a = 996.8(3), c = 2241.5(6) pm, wR2 = 0.0492, 2565 F2, 70 variables) have been refined from single-crystal diffractometer data. The structures are built up from complex threedimensional networks of edge- and corner-sharing RE6Ru trigonal prisms. Cavities within these networks are filled by slightly elongated Mg4 tetrahedra (311 - 315 pm in Pr23Ru7Mg4) and RE6 octahedra. The cerium compound has an a parameter which is even smaller than that of Nd23 Ru7Mg4, indicating intermediate-valent cerium. This was confirmed by magnetic susceptibility measurements. Ce23Ru7Mg4 shows an average, reduced magnetic moment of 2.01 μB/Ce atom. Pr23Ru7Mg4 contains stable trivalent praseodymium (3.64 μB/Pr atom)

Intermediate-valent Cerium in Ce2Ru4Mg17 and a Group-Subgroup Scheme for La9Ru4In5 and Ce9Ru4Ga5

2012 ◽  
Vol 67 (3) ◽  
pp. 219-225 ◽  
Author(s):  
Stefan Linsinger ◽  
Rolf-Dieter Hoffmann ◽  
Matthias Eul ◽  
Rainer Pöttgen
Keyword(s):  
Magnetic Ordering ◽  
Direct Consequence ◽  
Structure Type ◽  
Magnetic Susceptibility Data ◽  
Space Group ◽  
Susceptibility Data ◽  
Structural Distortions ◽  
Subgroup Scheme ◽  
Tetravalent Cerium ◽  
Intermediate Valent

Ce2Ru4Mg17 was synthesized by high-frequency melting of the elements in a sealed tantalum ampoule. This magnesium-rich compound crystallizes with a new tetragonal structure type: I4̄2m, a = 986.75(8), c = 1008.7(1) pm, wR2 = 0.0513, 909 F2 values and 34 variables. The striking structural motifs in the Ce2Ru4Mg17 structure are slightly bent CeRu2 units with short Ce-Ru distances of 231 pm and additionally a short Ce-Ce distance of 307 pm. These features are a direct consequence of the cerium valence. The CeRu2 units are embedded in a magnesium-rich matrix with a broad range of Mg-Mg distances (291 - 361 pm). Temperature-dependent magnetic susceptibility data show intermediate-valent behavior of the cerium atoms (0.23(5) μB per Ce atom) and no magnetic ordering down to 3 K, indicative of almost tetravalent cerium in Ce2Ru4Mg17. The ceriumrich gallide Ce9Ru4Ga5 shows an unusually short Ce-Ru distance of 237 pm for the Ce2 position as a result of an intermediate cerium valence. The structural distortions are discussed on the basis of a group-subgroup scheme for La9Ru4In5 (space group I4/mmm) and the superstructure variant Ce9Ru4Ga5 (space group I4mm).

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