Search results for " susceptibility"
showing 10 items of 827 documents
Crystal field effects and magnetic properties of Dy2Te3
1995
Abstract Magnetic susceptibility and magnetization measurements are presented for Dy 2 Te 3 . By means of crystal field calculations the energy levels of ground state and crystal field potentials for Dy 3+ ions have been evaluated taking the exchange interactions into account.
Neutron diffraction studies of the molecular compound [Co 2(bta)]n (H4bta =1,2,4,5-benzenetetracarboxylic acid): In the quest of canted ferromagnetism
2013
The exchange mechanism and magnetic structure of the organic-inorganic layered molecule-based magnet [Co2(bta)]n (1) (H 4bta =1,2,4,5-benzenetetracarboxylic acid) have been investigated through variable-temperature magnetic susceptibility measurements and supported with a series of neutron diffraction experiments. Cryomagnetic studies have shown an antiferromagnetic ordering at a transition temperature of 16 K that is followed by the appearance of a weak ferromagnetism below 11 K. The weak antiferromagnetic interlayer interaction plays an important role in this system in spite of the long interlayer separation. A ferromagnetic ordering is induced by applied magnetic fields greater than 1800…
Structure and Properties of GdAuSn and the GdAuSn/MnAuSn System
2006
The crystal structure of GdAuSn was refined by means of single crystal X-ray diffraction. Band structure calculations based on the structural data confirmed the antiferromagnetic ground state and the metallic behaviour of GdAuSn. 119mSn, 155Gd and 197Au Mossbauer spectroscopic studies were used to verify the values of the hyperfine parameters that were given by the band structure calculations. Band structure calculations of MnAuSn confirmed that this half-Heusler compound belongs to the family of half-metallic ferromagnets. Magnetic susceptibility, conductivity and Mossbauer studies were used to characterize granular material based on the half-Heusler ferromagnet MnAuSn in the antiferromagn…
Debye-Waller factor in the spin crossover complex Fe(ppi)2(NCS)2
1997
Abstract Mossbauer spectroscopy and magnetic susceptibility measurements for the complex Fe(ppi) 2 (NCS) 2 in the temperature range 11–300 K indicate that the spin transition of this compound is incomplete until 11 K. The similar Debye-Waller factors in high spin (HS) and low spin (LS) states is shown by the comparison of the HS fractions from the two different methods. The Debye temperature of the compound was calculated from the defined Debye-Waller factors obtained from Mossbauer measurement at each experimental temperature and was found to depend on the temperature as well as on the HS fraction. The modification of the Debye-Waller factors in the HS and LS states for the HS fraction fro…
Temperature and pressure effects on the spin state of ferric ions in the [Fe(sal2-trien)][Ni(dmit)2] spin crossover complex
2008
Abstract Thermal and pressure effects have been investigated on the [Fe(sal 2 -trien)][Ni(dmit) 2 ] spin crossover complex by means of Mossbauer spectroscopic, calorimetric, X-ray diffraction and magnetic susceptibility measurements. The complex displays a complete thermal spin transition between the S = 5 2 and S = 1 2 spin states of Fe III near 245 K with a hysteresis loop of ca. 30 K. This transition is characterised by a change of the enthalpy, Δ H HL =7 kJ/mol, entropy, Δ S HL =29 J/Kmol, and the unit cell volume, Δ V HL =15.4 A 3 . Under hydrostatic pressures up to 5.7 kbar the thermal transition shifts to higher temperatures by ca. 16 K/kbar. Interestingly, at a low applied pressure …
Spin crossover behaviour in the iron(II)-2,2-dipyridilamine system: Synthesis, X-ray structure and magnetic studies
2005
Abstract The monomeric compounds [Fe(dpa)2(X)2] · solv [X = NCS−(solv = 0.5H2O) (1), N ( CN ) 2 - (2) and dpa = 2,2-dipyridilamine] have been synthesised and characterised. They crystallise in the P21/n and in the Cc monoclinic systems, respectively. Four of six nitrogen atoms coordinated to the Fe(II) ions belong to two dpa ligands which lie in cis conformation. The remaining positions are occupied by two nitrogen atoms of the pseudo-halide ligands. The magnetic susceptibility measurements at ambient pressure have revealed that compound 1 exhibits an incomplete spin crossover behaviour (T1/2 ≈ 88 K), whereas compound 2 remains in the high-spin configuration. Pressure studies performed on c…
The diagnosis and management of gastric cancer: Expert discussion and recommendations from the 12th ESMO/World Congress on Gastrointestinal Cancer, B…
2011
Well-recognized experts in the field of gastric cancer discussed during the 12th European Society Medical Oncology (ESMO)/World Congress Gastrointestinal Cancer (WCGIC) in Barcelona many important and controversial topics on the diagnosis and management of patients with gastric cancer. This article summarizes the recommendations and expert opinion on gastric cancer. It discusses and reflects on the regional differences in the incidence and care of gastric cancer, the definition of gastro-esophageal junction and its implication for treatment strategies and presents the latest recommendations in the staging and treatment of primary and metastatic gastric cancer. Recognition is given to the ne…
Coordination polymers based on bridging cyanocarbanions and bis-tridentate p-phenylenediamine ligands
2017
Two new Cu(II) coordination polymeric neutral chains of formula [Cu 2 (1,4-tpbd)(μ-A) 2 (H 2 O) 2 ](A) 2 with A = tcnoet − ( 1 ) and tcnopr − ( 2 ) (1,4-tpbd = N,N,N′N′ -tetrakis(2-pyridylmethyl)benzene-1,4-diamine, tcnoet − = 1,1,3,3-tetracyano-2-ethoxypropenide and tcnopr − = 1,1,3,3-tetracyano-2-propoxypropenide) have been synthesized and characterized by infrared spectroscopy, X-ray diffraction and magnetic measurements. 1 and 2 show alternating chains where the 1,4-tpbd and the cyanocarbanion units (tcnoet − for 1 and tcnopr − for 2 ) alternate as bridging ligands. The molecular structure can be viewed as [Cu 2 (μ-tpbd)] 4+ dinuclear units (with Cu⋯Cu distances of 8.2233(3) for 1 …
A Copper(II)-Cytidine Complex as a Building Unit for the Construction of an Unusual Three-Dimensional Coordination Polymer
2010
The chiral [Cu(cyd) 4 ] 6- anion acts as a multiarmed complex-ligand toward auxiliary copper(II) centers leading to the first example of cytidinate-bridged three-dimensional (3D) coordination polymer of formula [Cu 6 (H 2 O) 7 (ClO 4 ) 3 Cu(cyd) 4 ]-(ClO 4 ) 3 (1). Single crystal X-ray analysis of 1 shows a unique 3D covalent network supported by the exclusive hypercoordination of the cytidinate ligand that bridges four crystallographically independent copper(II) ions via the N3, O2, O2', O3', and O5' set of atoms. Magnetic susceptibility measurements in the temperature range 1.9-295 K reveal the coexistence of ferro- and antiferromagnetic interactions within the hexacopper(II) core of 1, t…
Structural, magnetic and electrical properties of one-dimensional tetraamidatodiruthenium compounds
2013
The first bromo and iodo tetraamidatodiruthenium compounds of the type [Ru2X(μ-NHOCC6H4-R)4]n [X = Br, R = o-Me (1), m-Me (2), p-Me (3); X = I, R = o-Me (4), m-Me (5), p-Me (6)] have been prepared using solvothermal or microwave activation procedures. In these reactions ethanol or methanol as solvents have been used to make the synthesis procedures more environment-friendly. Solvothermal synthesis has allowed us to isolate single crystals of these extremely insoluble compounds and the crystal structures of all of them have been determined using single crystal X-ray diffraction. The change of the bridging halide ligand permits us to discuss the properties of these complexes on the basis of t…