Crystal Structure and Magnetic Ordering Transitions in CeNiIn4, EuNiIn4 and EuCuIn4

2014 ◽  
Vol 69 (9-10) ◽  
pp. 1003-1009 ◽  
Author(s):  
Walter Schnelle ◽  
Reinhard K. Kremer ◽  
Rolf-Dieter Hoffmann ◽  
Ute Ch. Rodewald ◽  
Rainer Pöttgen
Keyword(s):  
Low Temperatures ◽  
Three Dimensional ◽  
Magnetic Ordering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Specific Heats ◽  
Antiferromagnetic Ordering ◽  
Arc Melting ◽  
Ordering Transitions ◽  
The Eu

Abstract Polycrystalline CeNiIn4 was prepared by arc-melting of the elements and subsequent annealing at 970 K in vacuum. EuNiIn4 and EuCuIn4 were synthesized from the elements by reactions in sealed tantalum tubes. These indium-rich compounds crystallize with the YNiAl4-type structure which was refined for EuCuIn4 from single-crystal X-ray diffraction data: Cmcm, a=450:04(9), b=1698:7(4), c = 740:2(2) pm, wR2 = 0:0606, 495 F2 values, 24 variables. The EuCuIn4 structure is built up from a complex three-dimensional [CuIn4] polyanion (265 - 279 pm Cu-In and 296 - 331 pm In- In) in which the europium atoms occupy distorted hexagonal channels. The Eu-Eu distances within these channels (450 pm) are significantly shorter than the distances between Eu atoms in neighboring channels (552 pm). The magnetic properties and the specific heats of the europium compounds have been investigated. Both europium compounds show the magnetism of divalent Eu ions and antiferromagnetic ordering at low temperatures. EuCuIn4 is magnetically ordered via a surprisingly complex sequence of three transitions

Ternary Antimonides RE2Ir3Sb4 (RE = La, Ce, Pr, Nd)

2011 ◽  
Vol 66 (8) ◽  
pp. 777-783
Author(s):  
Konrad Schäfer ◽  
Wilfried Hermes ◽  
Ute Ch. Rodewald ◽  
Rolf-Dieter Hoffmann ◽  
Rainer Pöttgen
Keyword(s):  
High Frequency ◽  
Three Dimensional ◽  
Magnetic Ordering ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Static Disorder ◽  
X Ray ◽  
Coordination Numbers ◽  
Arc Melting ◽  
Covalently Bonded

The antimonides RE2Ir3Sb4 (RE = La, Ce, Pr, Nd) were synthesized by arc-melting of the elements and subsequent annealing or via high-frequency melting. The samples were characterized by X-ray powder diffraction, and the four structures were refined from single-crystal X-ray diffraction data: Pr2Ir3Sb4 type, Pnma, Z = 4, a = 1621.9(2), b = 458.60(8), c = 1099.8(1) pm, wR2 = 0.036, 1558 F2 values for La2Ir3Sb4, a = 1616.6(8), b = 456.5(2), c = 1094.8(5) pm, wR2 = 0.092, 1080 F2 values for Ce2Ir3Sb4, a = 1613.0(5), b = 454.9(2), c = 1094.1(5) pm, wR2 = 0.057, 1428 F2 values for Pr2Ir3Sb4, and a = 1609.8(6), b = 452.9(2), c = 1092.3(5) pm, wR2 = 0.052, 1472 F2 values for Nd2Ir3Sb4, with 56 parameters per refinement. The Sb1 atoms show enhanced displacement off the mirror planes at y = 1/4 and y = 3/4. A series of temperature-dependent structure refinements of Pr2Ir3Sb4 down to 90 K are indicative of static disorder. The iridium and antimony atoms build up covalently bonded three-dimensional [Ir3Sb4] networks with Ir-Sb distances ranging from 256 -269 pm (Nd2Ir3Sb4). The two crystallographically independent rare earth sites fill cavities of coordination numbers 17 (8 Ir + 9 Sb) and 15 (6 Ir + 9 Sb) within the [Ir3Sb4] polyanions. Temperature-dependent magnetic susceptibility measurements indicate a stable trivalent ground state for the cerium compound. No magnetic ordering was evident down to 3 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

Structure Refinement of CePtSi and Hydrogenation Behavior of CePdGe, CePtSi and CePtGe

2007 ◽  
Vol 62 (4) ◽  
pp. 613-616 ◽  
Author(s):  
Wilfried Hermes ◽  
Ute Ch. Rodewald ◽  
Bernard Chevalier ◽  
Rainer Pötgena
Keyword(s):  
Single Crystal ◽  
Diffraction Data ◽  
Structure Refinement ◽  
Three Dimensional ◽  
Subsequent Annealing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydride Formation ◽  
Arc Melting ◽  
Cerium Compounds

The intermetallic cerium compounds CePdGe, CePtSi, and CePtGe were synthesized from the elements by arc-melting and subsequent annealing. The structure of CePtSi was refined from single crystal X-ray diffraction data: LaPtSi-type (ordered α-ThSi2 version), 141md, a = 419.6(1) and c = 1450.0(5) pm, wR2 = 0.0490, 362 F2 values and 16 variables. The Pt-Si distances within the three-dimensional [PtSi] network are 242 pm, indicating strong Pt-Si interactions. Hydrogenation of the three compounds at 623 K and 4 MPa H2 gave no indication for hydride formation.

Superconductivity and Magnetic Ordering of Pr in CaLa1-xPrxBaCu3O7 System

1997 ◽  
Vol 11 (07) ◽  
pp. 323-331 ◽  
Author(s):  
V. P. S. Awana ◽  
Rajvir Singh ◽  
D. A. Landinez Tellez ◽  
J. M. Ferreira ◽  
J. Albino Aguiar ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Normal State ◽  
Ac Susceptibility ◽  
Magnetic Ordering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Antiferromagnetic Ordering ◽  
Peak Intensity ◽  
Heat Capacity Measurements ◽  
A Minor

We present the results of superconductivity, normal state magnetic susceptibility and heat capacity measurements on the tetragonal CaLa 1-x Pr x BaCu 3 O 7 compound. Ac susceptibility measurements show that the transition temperature T c of the unsubstituted sample decreases with an increase in the Pr concentration. Normal state dc magnetic susceptibility measurements performed in an applied field of 0.5 T show a Curie–Weiss behaviour in terms of the paramagnetic moment of Pr. The effective paramagnetic moment of Pr appears to be intermediate between those of the free Pr 3+ and Pr 4+ ions. For the nonsuperconducting samples i.e., x = 0.70 and 1.0, we observe an antiferromagnetic ordering temperature T N of nearly 4 K and 8 K respectively. The X-ray diffraction results show that the CaPrBaCu 3 O 7 compound is free from other phases, having a minor (less than 8%, in terms of peak intensity) impurity phase. The lower T N (8 K) of PrBaCaCu 3 O 7 as compared to the known antiferromagnetic ordering temperature of 17 K for PrBa 2 Cu 3 O 7 indicates a less deleterious effect of Pr in the present case.

Ternary Stannides RE3Ru4Sn13 (RE = La, Ce, Pr, Nd) – Structure, Magnetic Properties, and 119Sn Mössbauer Spectroscopy

2011 ◽  
Vol 66 (7) ◽  
pp. 664-670
Author(s):  
◽  
Christian Schwickert ◽  
Thorsten Langer ◽  
Rainer Pöttgen
Keyword(s):  
Mössbauer Spectroscopy ◽  
Mossbauer Spectroscopy ◽  
Three Dimensional ◽  
Magnetic Ordering ◽  
119Sn Mössbauer Spectroscopy ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Mößbauer Spectroscopy ◽  
Arc Melting ◽  
Different Types

The ternary stannides RE3Ru4Sn13 (RE = La, Ce, Pr, Nd) were obtained by arc-melting of the elements. The polycrystalline samples were characterized by powder X-ray diffraction. The structures of three compounds were refined from single-crystal diffractometer data: Yb3Rh4Sn13 type, Pm3̄n, a = 977.74(3) pm, wR2 = 0.0379, 280 F2 values for La3Ru4Sn13, a = 971.34(9) pm, wR2 = 0.0333, 274 F2 values for Ce3Ru4Sn13, a = 970.68(8) pm, wR2 = 0.0262, 272 F2 values for Nd3Ru4Sn13 with 13 variables per refinement. The structures consist of three-dimensional networks of condensed RuSn6/2 trigonal prisms with the RE (CN 16) and Sn2 (CN 12) atoms in two different types of cavities of the networks. The two crystallographically independent tin sites have been resolved by 119Sn Mössbauer spectroscopy. Temperature-dependent magnetic susceptibility measurements of Ce3Ru4Sn13 gave a reduced magnetic moment of 2.32 μB per Ce atom, indicating intermediate cerium valence. No magnetic ordering was evident down to 3 K.

Magnetic properties of the germanides RE3Pt4Ge6 (RE=Y, Pr, Nd, Sm, Gd–Dy)

2017 ◽  
Vol 72 (11) ◽  
pp. 855-864 ◽  
Author(s):  
Fabian Eustermann ◽  
Matthias Eilers-Rethwisch ◽  
Konstantin Renner ◽  
Rolf-Dieter Hoffmann ◽  
Rainer Pöttgen ◽  
...  
Keyword(s):  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Modulated Structure ◽  
X Ray ◽  
Antiferromagnetic Ordering ◽  
Arc Melting ◽  
Pauli Paramagnetism ◽  
Van Vleck Paramagnetism ◽  
Van Vleck ◽  
Vleck Paramagnetism

AbstractThe germanides RE3Pt4Ge6 (RE=Y, Pr, Nd, Sm, Gd–Dy) have been synthesized by arc-melting of the elements followed by inductive annealing to improve the crystallinity and allow for structural order. The compounds have been studied by powder X-ray diffraction; additionally the structure of Y3Pt4Ge6 has been refined from single-crystal X-ray diffractometer data. It exhibits a (3+1)D modulated structure, indicating isotypism with Ce3Pt4Ge6. The crystal structure can be described as an intergrowth between YIrGe2- and CaBe2Ge2-type slabs along [100]. Temperature-dependent magnetic susceptibility measurements showed Pauli paramagnetism for Y3Pt4Ge6 and Curie-Weiss paramagnetism for Pr3Pt4Ge6 and Nd3Pt4Ge6. Sm3Pt4Ge6 exhibits van Vleck paramagnetism, while antiferromagnetic ordering at TN=8.1(1) K and TN=11.0(1) K is observed for Gd3Pt4Ge6 and Tb3Pt4Ge6, respectively.

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.

Two series of rare earth metal-rich ternary aluminium transition metallides – RE6Co2Al (RE=Sc, Y, Nd, Sm, Gd–Tm, Lu) and RE6Ni2.25Al0.75 (RE=Y, Gd–Tm, Lu)

2018 ◽  
Vol 73 (11) ◽  
pp. 927-942 ◽  
Author(s):  
Frank Stegemann ◽  
Oliver Janka
Keyword(s):  
Rare Earth ◽  
Single Crystal ◽  
Rare Earth Metal ◽  
Magnetic Measurements ◽  
Earth Metal ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Antiferromagnetic Ordering ◽  
Arc Melting

AbstractThe rare earth metal-rich cobalt and nickel aluminium compounds with the general compositions RE6Co2Al (RE=Sc, Y, Nd, Sm, Gd–Tm, Lu) and RE6Ni2.25Al0.75 (RE=Y, Gd–Tm, Lu) have been synthesised from the elements by arc-melting, followed by annealing. Single-crystal X-ray diffraction experiments on Y6Co2.02(1)Al0.98(1) (Ho6Co2Ga type; Immm; a=944.1(2), b=952.4(2), c=999.0(2) pm; wR2=0.0452, 1123 F2 values, 35 variables) and Y6Ni2.26(1)Al0.74(1) (Ho6Co2Ga type; Immm; a=938.30(5), b=959.45(5), c=996.05(6) pm; wR2=0.0499, 1131 F2 values, 35 variables) revealed that the compounds form solid solutions according to the general formula RE6(Co/Ni)2+xAl1−x with different homogeneity ranges. The compounds of the Ni series can be obtained in X-ray pure form only with the nominal composition RE6Ni2.25Al0.75. A significant increase of the U22 component of the anisotropic displacement parameters of the Co/Ni2 atoms (4g site) was observed that requires a description of the structure with a split-position model at RT. Further investigations by low temperature (90 K) single-crystal X-ray diffraction experiments of Y6Co2.02(1)Al0.98(1) showed a significant decrease of U22. Magnetic measurements were conducted on the X-ray pure members of the RE6Co2Al (RE=Y, Dy–Tm, Lu) series. Antiferromagnetic ordering was observed for the members with unpaired f electrons with Néel temperatures up to TN=48.0(1) K and two spin reorientations for Dy6Co2Al.

The X-Ray Analysis and Mössbauer Studies Mn-V-Sn Alloys

2010 ◽  
Vol 163 ◽  
pp. 221-224
Author(s):  
Aneta Hanc ◽  
Grzegorz Dercz ◽  
Izabela Jendrzejewska
Keyword(s):  
Mössbauer Spectroscopy ◽  
Mossbauer Spectroscopy ◽  
Magnetic Ordering ◽  
X Ray Diffraction ◽  
Atomic Concentration ◽  
X Ray ◽  
Mößbauer Spectroscopy ◽  
Arc Melting ◽  
Independent Information ◽  
Binary Compounds

The aim of the work is to search possibility for preparation of the Mn2VSn and V2MnSn Heusler-type compounds. We have carried out the 119Sn-Mössbauer spectroscopy, scanning electron microscopy and X-ray diffraction studies on the some Mn0.5V0.25 Sn0.25 and V0.5Mn0.25Sn0.25 solid solutions prepared by arc melting of the constituent metals. Combining an independent information about atomic structure from X-ray diffraction and Mössbauer spectroscopy it was possible to identify main chemical environments responsible for the magnetic ordering observed in the samples. The studies revealed that investigated alloys are characterized by existence of the binary compounds, namely V2Sn3, V3Sn and Mn3Sn, with different extension in Mn and V atomic concentration, respectively. No ternary compounds were found in investigated systems.

Ternary rhombohedral Laves phases RE2Rh3Ga (RE = Y, La–Nd, Sm, Gd–Er)

2017 ◽  
Vol 72 (4) ◽  
pp. 289-303 ◽  
Author(s):  
Stefan Seidel ◽  
Oliver Janka ◽  
Christopher Benndorf ◽  
Bernhard Mausolf ◽  
Frank Haarmann ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Susceptibility ◽  
Rare Earth ◽  
Low Temperatures ◽  
Nmr Spectra ◽  
X Ray Diffraction ◽  
Laves Phases ◽  
X Ray ◽  
Arc Melting ◽  
Pauli Paramagnetism

Abstract:The ordered Laves phases RE2Rh3Ga (RE=Y, La–Nd, Sm, Gd–Er) were synthesized by arc-melting of the elements and subsequent annealing. The samples were characterized by powder X-ray diffraction (XRD). They crystallize with the rhombohedral Mg2Ni3Si type structure, space group R3̅m. Three structures were refined from single crystal X-ray diffractometer data: a=557.1(1), c=1183.1(2), wR2=0.0591, 159 F2 values, 10 variables for Y2Rh3Ga, a=562.5(2), c=1194.4(2) pm, wR2=0.0519, 206 F2 values, 11 variables for Ce2Rh3Ga and a=556.7(2), c=1184.1(3) pm, wR2=0.0396, 176 F2 values, 11 variables for Tb2Rh3Ga. The Rh3Ga tetrahedra are condensed via common corners and the large cavities left by the network are filled by the rare earth atoms. The RE2Rh3Ga Laves phases crystallize with a translationengleiche subgroup of the cubic RERh2 Laves phases with MgCu2 type. Magnetic susceptibility measurements reveal Pauli paramagnetism for Y2Rh3Ga and La2Rh3Ga. Ce2Rh3Ga shows intermediate cerium valence while all other RE2Rh3Ga phases are Curie–Weiss paramagnets which order magnetically at low temperatures. The 89Y and 71Ga solid state nuclear magnetic resonance (NMR) spectra of the diamagnetic representative Y2Rh3Ga show well-defined single resonances in agreement with an ordered bulk phase. In comparison to the binary Laves phase YRh2 a strongly increased 89Y resonance frequency is observed owing to a higher s-electron spin density at the 89Y nuclei as proven by density of states (DOS) calculations.

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