64 research outputs found
ScIrP with ZrNiAl-type Structure
The phosphide ScIrP was synthesized from the elements in a bismuth flux and characterized by powder and singlecrystal X-ray diffraction: ZrNiAl type, P62m, Z = 3, a = 637.2(3), c = 389.2(2) pm, wR2 = 0.0280, 250 F 2 values, 15 variables. The two crystallographically independent phosphorus sites have tricapped trigonal-prismatic metal coordination P1Ir 3 Sc 6 and P2Ir 6 Sc 3 . The shortest interatomic distances occur for Ir-P (244 -251 pm) within the 3D [IrP] network in which the scandium atoms fill cavities of coordination number 15 (4 Sc + 6 Ir + 5 P)
Single Crystal Structure of the Divalent Europium Chloroapatite Eu 5 (PO 4 ) 3 Cl
The chloroapatite Eu 5 (PO 4 ) 3 Cl has been synthesized by a solid-state reaction route using a salt flux. Its structure has been solved and refined from single crystal X-ray data: apatite type, P6 3 /m, a = 988.36(4), c = 720.32(3) pm, Z = 2, R(F) = 0.021 and wR(F 2 ) = 0.063 for 748 unique reflections and 40 variables. The Eu 5 (PO 4 ) 3 Cl structure contains isolated (PO 4 ) 3− tetrahedra and two crystallographically independent divalent europium sites. The Eu1 2+ ion at the 4 f position is located in a distorted tri-capped trigonal prism whereas the Eu2 2+ ion at the 6h position is located in a strongly distorted square anti-prism. The chloride ions have octahedral europium coordination (307 pm Eu-Cl)
Large reversible magnetocaloric effect due to a rather unstable antiferromagnetic ground state in Er4NiCd
Er4NiCd crystallizes with the Gd4RhIn type structure, space group F (4) over bar 3m, a=1333.3 pm. The nickel atoms have trigonal prismatic rare earth coordination. Condensation of the NiEr6 prisms leads to a three-dimensional network which leaves voids that are filled by regular Cd-4 tetrahedra. Er4NiCd shows Curie-Weiss behavior above 50 K with T-N=5.9 K. At field strength of 4 kOe a metamagnetic step is visible, together with the positive paramagnetic Curie-temperature (7.5 K) indicative for the rather unstable antiferromagnetic ground state. Therefore, a large reversible magnetocaloric effect (MCE) near the ordering temperature occurs and the values of the maximum magnetic-entropy change -Delta S-M(max) reach 18.3 J kg(-1) K-1 for the field change of 5 T with no obvious hysteresis loss around 17 K. The corresponding RCP of 595 J kg(-1) is relatively high as compared to other MCE materials in that temperature range. These results indicate that Er4NiCd could be a promising system for magnetic refrigeration at temperatures below liquid H-2. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3518556
Rare earth–transition metal–magnesium compounds—An overview
Intermetallic rare earth–transition metal–magnesium compounds play an important role as precipitations in modern light weight alloys and as host materials for hydrogen storage applications..
Rare Earth-rich Cadmium Compounds RE 4 TCd (T = Ni, Pd, Ir, Pt)
New intermetallic compounds RE 4 T Cd (RE = Y, La-Nd, Sm, Gd-Tm, Lu; T = Ni, Pd, Ir, Pt) were synthesized by melting of the elements in sealed tantalum tubes in a highfrequency furnace. They crystallize with the Gd 4 RhIn-type structure, space group F43m, Z = 16. The four gadolinium compounds were characterized by single crystal X-ray diffractometer data: a = 1361.
Rare Earth-rich Magnesium Compounds RE4RhMg (1{RE} = Y, La - Nd, Sm, Gd - Tm, Lu)
The series of magnesium compounds RE4RhMg (RE = Y, La–Nd, Sm, Gd–Tm, Lu) was prepared by high-frequency melting of the elements in sealed tantalum tubes..
Structure refinement of CePtSi and hydrogenation behavior of CePdGe, CePtS and CePtGe
The intermetallic cerium compounds CePdGe, CePtSi, and CePtGe were synthesized from the elements by arc-melting and subsequent annealing..
Rare Earth-rich Magnesium Compounds RE4RhMg (1{RE} = Y, La - Nd, Sm, Gd - Tm, Lu)
The series of magnesium compounds RE4RhMg (RE = Y, La–Nd, Sm, Gd–Tm, Lu) was prepared by high-frequency melting of the elements in sealed tantalum tubes..
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