Structural and magnetic characterization of Ho3SbO7 and Dy3SbO7

2001 ◽  
Vol 79 (11-12) ◽  
pp. 1415-1419 ◽  
Author(s):  
T Fennell ◽  
S T Bramwell ◽  
M A Green

We present an experimental investigation of the structural and magnetic properties of Ho3SbO7 and Dy3SbO7. These compounds adopt the Y3TaO7 structure, space group C2221. The magnetic rare-earth ions occupy an intricate lattice related to the pyrochlore lattice that occurs in Ho2Ti2O7 and Dy2Ti2O7. The crystal structure of Ho3SbO7 is determined by Rietveld refinement of the powder X-ray diffraction pattern at ambient temperature, and that of the Dy analogue is inferred to be similar. Magnetic susceptibility measurements show that Ho3SbO7 and Dy3SbO7 have negative Curie–Weiss temperatures: –8.4 K (Ho) and –9.2 K (Dy). Magnetic transitions have been detected at 2.0 K (Ho) and 3.0 K (Dy). We discuss the results in terms of the ``dipolar spin ice model'' that has been used to describe Ho2Ti2O7 and Dy2Ti2O7. PACS Nos.: 75.25+z, 75.50Ee, 61.10Nz

2015 ◽  
Vol 70 (8) ◽  
pp. 527-531 ◽  
Author(s):  
Daopeng Zhang ◽  
Lingqian Kong ◽  
Hongyan Zhang ◽  
Ping Wang

AbstractBy using K4[Mo(CN)8] and [Ni(L)(H2O)2][ClO4]2 as reagents (L = 2,12-dimethyl-3,7,11,17-tetraazabicyclo [11.3.1]heptadeca-1(17),13,15-triene), a new cyanide-bridged Mo–Ni complex containing the building blocks [Ni(H2O)(L)]2+ and [Ni(L)]2+ bridged by [Mo(CN)8]4− units has been obtained. The complex with the formula {[Ni(H2O)(L)][Ni(L)][Mo(CN)8]}6 · 36H2O · 2CH3OH (1) was characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. The structure determination reveals an octadecanuclear cluster in the form of a 36-membered macrocycle, in which the largest intramolecular W···W and Ni···Ni distances are 16.5 and 14.4 Å, respectively, indicating that complex 1 is a nanosized molecular wheel. Investigation of its magnetic properties has shown weak antiferromagnetic coupling between the adjacent Ni(II) ions bridged by the diamagnetic [Mo(CN)8]4− ions.


2019 ◽  
Vol 74 (4) ◽  
pp. 381-387
Author(s):  
Michael Zoller ◽  
Jörn Bruns ◽  
Gunter Heymann ◽  
Klaus Wurst ◽  
Hubert Huppertz

AbstractA potassium tetranitratopalladate(II) with the composition K2[Pd(NO3)4] · 2HNO3 was synthesized by a simple solvothermal process in a glass ampoule. The new compound crystallizes in the monoclinic space group P21/c (no. 14) with the lattice parameters a = 1017.15(4), b = 892.94(3), c = 880.55(3) Å, and β = 98.13(1)° (Z = 2). The crystal structure of K2[Pd(NO3)4] · 2HNO3 reveals isolated complex [Pd(NO3)4]2− anions, which are surrounded by eight potassium cations and four HNO3 molecules. The complex anions and the cations are associated in layers which are separated by HNO3 molecules. K2[Pd(NO3)4] · 2HNO3 can thus be regarded as a HNO3 intercalation variant of β-K2[Pd(NO3)4]. The characterization is based on single-crystal X-ray and powder X-ray diffraction.


2020 ◽  
Vol 76 (1) ◽  
pp. 64-68 ◽  
Author(s):  
Hongya Li ◽  
Biao Yan ◽  
Haixia Ma ◽  
Zhiyong Sun ◽  
Yajun Ma ◽  
...  

Bis(5-amino-1,2,4-triazol-3-yl)methane (BATZM, C5H8N8) was synthesized and its crystal structure characterized by single-crystal X-ray diffraction; it belongs to the space group Fdd2 (orthorhombic) with Z = 8. The structure of BATZM can be described as a V-shaped molecule with reasonable chemical geometry and no disorder. The specific molar heat capacity (Cp,m ) of BATZM was determined using the continuous Cp mode of a microcalorimeter and theoretical calculations, and the Cp,m value is 211.19 J K−1 mol−1 at 298.15 K. The relative deviations between the theoretical and experimental values of Cp,m , HT – H 298.15K and ST – S 298.15K of BATZM are almost equivalent at each temperature. The detonation velocity (D) and detonation pressure (P) of BATZM were estimated using the nitrogen equivalent equation according to the experimental density; BATZM has a higher detonation velocity (7954.87 ± 3.29 m s−1) and detonation pressure (25.72 ± 0.03 GPa) than TNT.


2016 ◽  
Vol 71 (1) ◽  
pp. 51-55 ◽  
Author(s):  
Oscar E. Piro ◽  
Gustavo A. Echeverría ◽  
Beatriz S. Parajón-Costa ◽  
Enrique J. Baran

AbstractMagnesium acesulfamate, Mg(C4H4NO4S)2·6H2O, was prepared by the reaction of acesulfamic acid and magnesium carbonate in aqueous solution, and characterized by elemental analysis. Its crystal structure was determined by single crystal X-ray diffraction methods. The substance crystallizes in the triclinic space group P1̅ with one molecule per unit cell. The FTIR spectrum of the compound was also recorded and is briefly discussed. Some comparisons with other simple acesulfamate and saccharinate salts are also made.


2008 ◽  
Vol 63 (3) ◽  
pp. 345-348 ◽  
Author(s):  
Artem A. Babaryk ◽  
Igor V. Zatovsky ◽  
Nikolay S. Slobodyanik ◽  
Ivan V. Ogorodnyk

A new complex phosphate K1.84Fe1.42Nb0.58(PO4)3 has been synthesized by the self-flux technique. The X-ray single crystal structure and magnetic properties were studied. The compound crystallizes in the cubic system with space group P213 (a = 9.9404(10) Å ) and belongs to the langbeinite structure type. The structure contains [M2P3O18] building units. “Closed” fragments [M8P9O60] provide space for location of two potassium atoms. Antiferromagnetic interactions were detected at low temperatures which originate from superexchange through a M(1)-O-P-O-M(2) pathway with corresponding J = −5.5(1) cm−1. The relationship between the UV/vis absorption and the structure is discussed.


2008 ◽  
Vol 63 (5) ◽  
pp. 543-547 ◽  
Author(s):  
Inés Viera ◽  
Laura Domínguez ◽  
Javier Ellena ◽  
María H. Torre

This work reports the synthesis and characterization of a new copper complex with nadolol, a betablocker aminoalcohol. The stoichiometry found was Na[Cu(nadololate)(CO3)] · H2O. Electronic and vibrational spectroscopy analysis was performed, and the crystal structure of Na[Cu(nadololate)-(CO3)] · H2O was determined by X-ray diffraction.


2007 ◽  
Vol 119 ◽  
pp. 71-74 ◽  
Author(s):  
Yan Li ◽  
Xiao Li Zhang ◽  
Young Hwan Kim ◽  
Young Soo Kang

Co nanoparticles were synthesized via a solventless thermal decomposition of Co2+-oleate2. The crystalline structure is strongly affected by the thermal treatment of the Co nanoparticles. Further, the annealing also results in the decomposition of surfactant around Co particles. The size of nanoparticles was confirmed by transmission electron microscopy (TEM). The crystal structure of nanoparticles was characterized by X-ray diffraction pattern (XRD). The magnetic properties were characterized by vibrating sample magnetometer (VSM).


2013 ◽  
Vol 717 ◽  
pp. 133-138
Author(s):  
A. Awad Allah ◽  
M. Elhadi ◽  
O.A. Yassien

The crystal structure of both samples has been solved by powder X-ray diffraction, data in the tetragonal space group I4/m (a= b= 5.55182 Å, c =7.86955 A0) for SrLaFeNi0.5W0.5O6sample and (a=b= 5.49129Å, c= 7.82233Å) for CaLaFeNi0.5W0.5O6 sample, and shows an almost perfect ordering between Ni2+ and W5+ cations at the B-site of the perovskite structure. The FTIR spectrometer used of the powders showed that the spectra of both are very similar, showing two strong and well-defined absorption bands, typical of perovskite materials.


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