The equiatomic intermetallics REPtCd (RE= La, Ce, Pr, Nd, Eu) and magnetic properties of CeAuCd

2015 ◽  
Vol 70 (3) ◽  
pp. 197-202 ◽  
Author(s):  
Michael Johnscher ◽  
Frank Tappe ◽  
Oliver Niehaus ◽  
Rainer Pöttgen
Keyword(s):  
Phase Transition ◽  
Three Dimensional ◽  
Induction Melting ◽  
Antiferromagnetic Phase ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Magnetic Susceptibility Data ◽  
X Ray ◽  
Susceptibility Data

AbstractThe cadmium intermetallics REPtCd (RE = La, Ce, Pr, Nd, Eu) and CeAuCd were synthesized by induction-melting of the elements in sealed niobium ampoules followed by annealing in muffle furnaces. The samples were characterized by powder X-ray diffraction. The structures of CePtCd (ZrNiAl type, $P\bar 62m,$a = 763.8(6), c = 409.1(4) pm, wR2 = 0.0195, 298 F2 values, 14 variables) and EuPtCd (TiNiSi type, Pnma, a = 741.3(2), b = 436.4(1), c = 858.0(4) pm, wR2 = 0.0385, 440 F2 values, 20 variables) were refined from single-crystal data. The REPtCd structures exhibit three-dimensional networks of corner- and edge-sharing Cd@Pt2/6Pt2/3 and Cd@Pt4/4 tetrahedra, which leave cages for the rare earth atoms. Temperature-dependent magnetic susceptibility data of CeAuCd reveal a paramagnetic to antiferromagnetic phase transition at TN = 3.7(5) K.

Ferromagnetic interactions in a dicyanamide-bridged multinuclear metal-organic framework [Pr3NH]+ [Mn(dca)3]−·H2O

2019 ◽  
Vol 74 (6) ◽  
pp. 485-489
Author(s):  
Yuan Huang ◽  
Xiu-feng Yu ◽  
Zhen Rong ◽  
Yi-chun Ai ◽  
Kun Qian ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Magnetic Measurements ◽  
Metal Organic Framework ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Magnetic Susceptibility Data ◽  
X Ray ◽  
Susceptibility Data ◽  
Metal Organic ◽  
Ferromagnetic Interactions

AbstractA new complex [Pr3NH]+ [Mn(dca)3]− · H2O (dicyanamide = dca−) was synthesized, in which the Mn2+ cations are bridged by end-to-end dca anions to form three-dimensional [Mn(dca)3]nn− networks and tripropylammonium cations reside in the cavities of these networks. The complex has been characterized by single-crystal X-ray diffraction, infrared spectroscopy, elemental analysis, and magnetic measurements. Magnetic susceptibility data indicate ferromagnetic interactions among the MnII ions.

Ternary Indides REMgIn (RE = Y, La–Nd, Sm, Gd–Tm, Lu). Synthesis, Structure and Magnetic Properties

2004 ◽  
Vol 59 (5) ◽  
pp. 513-518 ◽  
Author(s):  
Rainer Kraft ◽  
Martin Valldor ◽  
Daniel Kurowski ◽  
Rolf-Dieter Hoffmann ◽  
Rainer Pöttgen
Keyword(s):  
Magnetic Moments ◽  
Three Dimensional ◽  
Temperature Dependent ◽  
Variable Parameters ◽  
Magnetic Susceptibility Data ◽  
X Ray ◽  
Susceptibility Data ◽  
Sample Chamber ◽  
Trigonal Prismatic Coordination ◽  
Trigonal Prismatic

Abstract The equiatomic rare earth-magnesium-indium compounds REMgIn (RE = Y, La-Nd, Sm, Gd- Tm, Lu) were prepared from the elements in sealed tantalum tubes inside a water-cooled sample chamber of an induction furnace. All compounds were characterized through their X-ray powder patterns. They crystallize with the hexagonal ZrNiAl type structure, space group P6̄̄2m, with three formula units per cell. The structure of SmMgIn was refined from X-ray single crystal diffractometer data: a = 761.3(2), c = 470.3(1) pm, wR2 = 0.0429, 380 F2 values and 14 variable parameters. The DyMgIn, HoMgIn, and TmMgIn structures have been analyzed using the Rietveld technique. The REMgIn structures contain two cystallographically independent indium sites, both with tri-capped trigonal prismatic coordination: In1Sm6Mg3 and In2Mg6Sm3. Together the magnesium and indium atoms form a three-dimensional [MgIn] network with Mg-Mg distances of 320 and Mg-In distances in the range 294 - 299 pm. Temperature dependent magnetic susceptibility data show Curie-Weiss behavior for DyMgIn, HoMgIn, and TmMgIn with experimental magnetic moments of 11.0(1) μB/Dy atom, 10.9(1) μB/Ho atom, and 7.5(1) μB/Tm atom. The three compounds order antiferromagnetically at TN = 22(2) K (DyMgIn), 12(1) K (HoMgIn), and 3(1) K (TmMgIn).

Structure and Properties of [(CH2OH)3CNH3]H2AsO4

2003 ◽  
Vol 58 (12) ◽  
pp. 722-726 ◽  
Author(s):  
A. Waśkowska ◽  
S. Dacko ◽  
Z. Czapla
Keyword(s):  
Phase Transition ◽  
Second Harmonic ◽  
Three Dimensional ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Dimensional Network ◽  
Network Of Hydrogen Bonds ◽  
Dependent Behaviour

Crystals of [(CH2OH)3CNH3]H2AsO4 have been grown, and X-ray diffraction analysis has shown them to be monoclinic, with space group P21. A three-dimensional network of hydrogen bonds of the type O-H. . . O and N-H. . . O forms strong cation-cation and cation-anion linkages. Stabilizing the structure, they create favourable conditions in the crystal to be polar. The temperature dependent behaviour of the dielectric permittivity, measured along three crystal axes in the range 100 - 300 K, did not show any evidence for a phase transition, while the pyroelectric properties of the crystal confirmed the lack of a centre of symmetry. These polar features locate [(CH2OH)3CNH3]H2AsO4 among the materials applicable to electrooptics and for the second harmonic generation.

Magnetic Properties of RE3Pd6Sb5 (RE = Pr, Nd,Gd) and a Group-Subgroup Scheme for Ce3Pd6Sb5 and Yb5Cu11Sn8

2011 ◽  
Vol 66 (10) ◽  
pp. 985-992
Author(s):  
Inga Schellenberg ◽  
Rolf-Dieter Hoffmann ◽  
Stefan Seidel ◽  
Christian Schwickert ◽  
Rainer Pöttgen
Keyword(s):  
Magnetic Ordering ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Magnetic Susceptibility Data ◽  
X Ray ◽  
Susceptibility Data ◽  
Low Field ◽  
Arc Melting ◽  
Subgroup Scheme ◽  
New Compounds

The Ce3Pd6Sb5-type antimonides RE3Pd6Sb5 (RE = Pr, Nd, Sm, Gd, Tb) were synthesized by arc-melting and subsequent annealing in sealed silica ampoules in a high-frequency furnace. The new compounds Sm3Pd6Sb5 (a = 1337.0(5), b = 441.5(1), c = 988.6(3) pm) and Tb3Pd6Sb5 (a = 1328.8(4), b = 439.9(2), c = 976.6(5) pm) were characterized by powder X-ray diffraction data. The RE3Pd6Sb5 antimonides adopt an ordered defect structure that derives from the CaBe2Ge2 type. Their crystal chemistry is compared to the structures of Ce8Rh17Sb14 and Yb5Cu11Sn8 on the basis of group-subgroup schemes. Temperature-dependent magnetic susceptibility data of the samples with RE = Pr, Nd and Gd show Curie-Weiss paramagnetism of the trivalent rare earths. Low-field susceptibility measurements reveal magnetic ordering at low temperatures.

Equiatomic rare earth rhodium plumbides RERhPb (RE=Y, La–Nd, Sm, Gd–Lu) with ZrNiAl-type structure

2018 ◽  
Vol 73 (3-4) ◽  
pp. 251-258
Author(s):  
Lukas Heletta ◽  
Rainer Pöttgen
Keyword(s):  
Type Structure ◽  
Induction Melting ◽  
Temperature Dependent ◽  
Magnetic Susceptibility Data ◽  
X Ray ◽  
Susceptibility Data ◽  
Pauli Paramagnetism ◽  
Antiferromagnetic Ground State ◽  
Trigonal Prismatic Coordination ◽  
Trigonal Prismatic

AbstractThe equiatomic plumbidesRERhPb (RE=Y, La–Nd, Sm, Gd–Lu) were synthesized by induction melting of the elements in sealed niobium ampoules. The samples were characterized by X-ray powder diffraction, confirming their ZrNiAl-type structure, space groupP6̅2m. Four structures were refined from single-crystal X-ray diffractometer data:a=769.42(5),c=415.60(3) pm,wR=0.0415, 343F2values, 15 variables for LaRhPb,a=767.91(6),c=369.37(4) pm,wR=0.0798, 284F2values, 15 variables for ErRhPb,a=767.01(8),c=366.21(4) pm,wR=0.0380, 341F2values, 15 variables for YbRhPb anda=766.9(1),c=363.42(6) pm,wR=0.0699, 290F2values, 15 variables for LuRhPb. TheRERhPb plumbides contain two crystallographically independent rhodium atoms, both in tricapped trigonal prismatic coordination: Rh1@Pb3RE6and Rh2@RE6Pb3. Short Rh–Pb distances (277 and 284 pm in ErRhPb) are indicative of covalent Rh–Pb bonding. The crystal chemical details of theRERhPb series are compared with the silver plumbidesREAgPb which show different transition metal-lead coloring. Temperature dependent magnetic susceptibility data show Pauli paramagnetism for YRhPb, LaRhPb and LuRhPb. An antiferromagnetic ground state below the Néel temperatures of 13.5, 21.0 and 6.9 K was found for PrRhPb, TbRhPb and DyRhPb, respectively. HoRhPb exhibits Curie-Weiss behavior in the observed temperature range.

The stannides REIr2Sn4 (RE=La, Ce, Pr, Nd, Sm)

2018 ◽  
Vol 73 (11) ◽  
pp. 875-884 ◽  
Author(s):  
Simon Engelbert ◽  
Dirk Niepmann ◽  
Theresa Block ◽  
Lukas Heletta ◽  
Rainer Pöttgen
Keyword(s):  
Three Dimensional ◽  
Structural Motif ◽  
Induction Melting ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Arc Melting ◽  
Van Vleck Paramagnetism ◽  
Splitting Parameter ◽  
Van Vleck

AbstractThe stannides REIr2Sn4 (RE=La, Ce, Pr, Nd, Sm) were synthesized from the elements by arc melting or by induction melting in sealed niobium containers. They crystallize with the NdRh2Sn4 type structure, space group Pnma. The samples were characterized by powder X-ray diffraction (Guinier technique). Three structures were refined from single-crystal X-ray data: a=1844.5(2), b=450.33(4), c=716.90(6) pm, wR2=0.0323, 1172 F2 values, 44 variables for LaIr2Sn4, a=1840.08(2), b=448.24(4), c=719.6(1) pm, wR2=0.0215, 1265 F2 values, 45 variables for Ce1.13Ir2Sn3.87, and a=1880.7(1), b=446.2(1), c=733.0(1) pm, wR2=0.0845, 836 F2 values, 45 variables for Ce1.68Ir2Sn3.32. The structures consist of three-dimensional [Ir2Sn4] polyanionic networks in which the rare earth atoms fill pentagonal prismatic channels. The striking structural motif concerns the formation of solid solutions RE1+xIr2Sn4−x on the Sn4 sites, which have similar coordination as the RE sites. Temperature dependent magnetic susceptibility measurements revealed diamagnetic behavior for LaIr2Sn4. CeIr2Sn4, PrIr2Sn4 and NdIr2Sn4 show Curie-Weiss paramagnetism while SmIr2Sn4 exhibits typical van Vleck paramagnetism. Antiferromagnetic ground states were observed for CeIr2Sn4 (TN=3.3 K) and SmIr2Sn4 (TN=3.8 K). 119Sn Mössbauer spectra show a close superposition of four sub-spectra which can be distinguished through their isomer shift and the quadrupole splitting parameter.

scholarly journals Intermetallic REPtZn Compounds with TiNiSi-type Structure

2011 ◽  
Vol 66 (7) ◽  
pp. 671-676 ◽  
Author(s):  
Trinath Mishra ◽  
Rainer Pöttgen
Keyword(s):  
Rare Earth ◽  
Single Crystal ◽  
Coordination Number ◽  
High Frequency ◽  
Three Dimensional ◽  
Type Structure ◽  
Rare Earth Compounds ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
X Ray

The equiatomic rare earth compounds REPtZn (RE = Y, Pr, Nd, Gd-Tm) were synthesized from the elements in sealed tantalum tubes by high-frequency melting at 1500 K followed by annealing at 1120 K and quenching. The samples were characterized by powder X-ray diffraction. The structures of four crystals were refined from single-crystal diffractometer data: TiNiSi type, Pnma, a = 707.1(1), b = 430.0(1), c = 812.4(1) pm, wR2 = 0.066, 602 F2, 21 variables for PrPt1.056Zn0.944; a = 695.2(1), b = 419.9(1), c = 804.8(1) pm, wR2 = 0.041, 522 F2, 21 variables for GdPt0.941Zn1.059; a = 688.2(1), b = 408.1(1), c = 812.5(1) pm, wR2 = 0.041, 497 F2, 22 variables for HoPt1.055Zn0.945; a = 686.9(1), b = 407.8(1), c = 810.4(1) pm, wR2 = 0.061, 779 F2, 20 variables for ErPtZn. The single-crystal data indicate small homogeneity ranges REPt1±xZn1±x. The platinum and zinc atoms build up three-dimensional [PtZn] networks (265 - 269 pm Pt-Zn in ErPtZn) in which the erbium atoms fill cages with coordination number 16 (6 Pt + 6 Zn + 4 Er). Bonding of the erbium atoms to the [PtZn] network proceeds via shorter RE-Pt distances, i. e. 288 - 293 pm in ErPtZn.

Ternary aurides RE4Mg3Au10 (RE=Y, Nd, Sm, Gd–Dy) and their silver analogues

2015 ◽  
Vol 70 (2) ◽  
pp. 135-141 ◽  
Author(s):  
Theresa Block ◽  
Michael Johnscher ◽  
Stefan Linsinger ◽  
Ute Ch. Rodewald ◽  
Rainer Pöttgen
Keyword(s):  
Three Dimensional ◽  
Intermetallic Phases ◽  
Point Of View ◽  
Site Preference ◽  
Induction Melting ◽  
X Ray Diffraction ◽  
X Ray ◽  
Synthesis Conditions ◽  
Coordination Numbers ◽  
Cation Sites

AbstractThe ternary aurides RE4Mg3Au10 (RE=Y, Nd, Sm, Gd–Dy) and their silver analogues were synthesized by induction melting of the elements in sealed niobium tubes. These intermetallic phases were characterized by powder X-ray diffraction. They crystallize with the Ca4In3Au10-type structure, which, from a geometrical point of view, is a ternary ordered version of Zr7Ni10 with the rare earth and magnesium atoms ordering on the four crystallographically independent zirconium sites. The structures of crystals from three differently prepared gadolinium samples were refined from single-crystal X-ray diffractometer data: Cmca, a=1366.69(3), b=998.07(4), c=1005.54(3) pm, wR2=0.0332, 1234 F2 values, 46 variables for Gd4.43Mg2.57Au10, a=1378.7(1), b=1005.3(1), c=1011.2(1) pm, wR2=0.0409, 1255 F2 values, 48 variables for Gd5.50Mg1.50Au10, and a=1350.2(5), b=995.5(1), c=1009.3(1) pm, wR2=0.0478, 1075 F2 values, 48 variables for Gd5.61Mg1.39Au10. All crystals show substantial Mg/Gd mixing on two sites. The gold atoms form a pronounced two-dimensional substructure with Au–Au distances of 278 to 297 pm in Gd4.43Mg2.57Au10. These gold blocks are condensed via magnesium atoms (278–315 pm Mg–Au). The gadolinium atoms fill larger cavities within the three-dimensional networks. The magnesium vs. gadolinium site preference is a consequence of the different coordination numbers of the cation sites. All phases show homogeneity ranges RE4+xMg3–xAg10 and RE4+xMg3–xAu10. The influence of the synthesis conditions is briefly discussed.

Structure and Magnetism of REPtMg (RE = Pr,Nd, Sm)

2002 ◽  
Vol 57 (5) ◽  
pp. 488-494 ◽  
Author(s):  
Rainer Kraft ◽  
Gunter Kotzyba ◽  
Rolf-Dieter Hoffmann ◽  
Rainer Pöttgen
Keyword(s):  
Spin Structure ◽  
Three Dimensional ◽  
Point Of View ◽  
Single Crystal Diffraction ◽  
Magnetic Susceptibility Data ◽  
X Ray ◽  
Susceptibility Data ◽  
Complex Spin ◽  
Ferromagnetic Ordering ◽  
Ordered State

New magnesium based intermetallic compounds PrPtMg, NdPtMg and SmPtMg were synthesized from the elements by reaction in sealed tantalum tubes in a high-frequency furnace. The three compounds were investigated by X-ray powder and single crystal diffraction: ZrNiAl type, space group P6̄2m, a = 752.34(8), c = 412.66(4) pm, wR2 = 0.0668, 341 F2 values, 14 variables for PrPtMg, a = 748.80(8), c = 411.52(4) pm, wR2 = 0.0521, 196 F2 values, 14 variables for NdPtMg and a = 743.90(5), c = 409.80(3) pm, wR2 = 0.0489, 248 F2 values, 12 variables for SmPtMg. From a geometrical point of view these structures are composed of two types of platinum centered trigonal prisms, i. e. [Pt1Mg3RE6] and [Pt2Mg6RE3]. These prisms are condensed via common edges and faces. Together the platinum and magnesium atoms build three-dimensional [PtMg] networks in which the rare earth atoms are located in distorted pentagonal channels. Magnetic susceptibility data of PrPtMg show Curie-Weiss behaviour with an experimentalmagnetic moment of 3.59(2) μB and a paramagnetic Curie temperature of 7.5(5) K. Ferromagnetic ordering is detected at TC = 8.0(5) K with a magnetic moment of 1.75(5) μB/Pr at 4.5 K and 5 T. SmPtMg orders ferromagnetically below 52(1) K with a presumably complex spin structure in the ordered state.

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