scholarly journals Spectroscopic, magnetic and thermal behaviour of the 2, 3, 4-trimethoxybenzoates of heavy lanthanides(III) and yttrium(III)

2004 ◽  
Vol 69 (3) ◽  
pp. 195-204 ◽  
Author(s):  
Wieslawa Ferenc ◽  
Beata Bocian ◽  
Agnieszka Walkow-Dziewulska
Keyword(s):  
Thermal Behaviour ◽  
Magnetic Moments ◽  
Carboxylate Group ◽  
Thermal Stabilities ◽  
Solubility In Water ◽  
Temperature Range ◽  
Heavy Lanthanide ◽  
Air Atmosphere ◽  
Chelating Ligand ◽  
Heavy Lanthanides

The complexes of 2,3,4-trimethoxybenzoic acid with Tb(III), Dy(III), Ho(III) Er(III), Tm(III), Yb(III), Lu(III) and Y(III) are crystalline, anhydrous salts with colours typical of the M(III) ions. The carboxylate group is probably a bidenate, chelating ligand. The thermal stabilities of the complexes were examined under an air atmosphere in the temperature range 293?1273 K. The solubility in water at 293 K for all the heavy lanthanide(III) and yttrium(III) complexes are in the order of 10-3 mol dm-3. The magnetic moments of the complexes were determined in the temperature range 77?300 K.

scholarly journals Magnetic, thermal and spectroscopic properties of 5-chloro-2-methoxybenzoates of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II)

2002 ◽  
Vol 67 (8-9) ◽  
pp. 605-615 ◽  
Author(s):  
Beata Bocian ◽  
Wieslawa Ferenc
Keyword(s):  
Thermal Properties ◽  
High Spin ◽  
Magnetic Moments ◽  
Spectroscopic Properties ◽  
Thermal Stabilities ◽  
Magnetic Susceptibilities ◽  
Temperature Range

The 5-chloro-2-methoxybenzoates of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) were synthesized as solids and their magnetic, spectral and thermal properties studied. The complexes possess colours typical of the M(II) ions. The thermal stabilities were examined in air and nitrogen atmospheres and the products of decompositions were also identified. The magnetic susceptibilities of the complexes were measured over the temperature range 4.4?300 K and the magnetic moments were calculated. The results show that the 5-chloro-2-methoxybenzoates of Mn(II), Co(II) and Ni(II) are octahedral high-spin complexes.

scholarly journals Magnetic, thermal and spectroscopic features of 2, 3- and 3, 5-dimethoxybenzoates of Co(II), Ni(II) and Cu(II)

2005 ◽  
Vol 70 (8-9) ◽  
pp. 1089-1104 ◽  
Author(s):  
Wieslawa Ferenc ◽  
Agnieszka Walków-Dziewulska ◽  
Jan Sarzynski
Keyword(s):  
Thermal Properties ◽  
Solid State ◽  
High Spin ◽  
Magnetic Moments ◽  
Thermal Stabilities ◽  
Decomposition Products ◽  
Magnetic Susceptibilities ◽  
Temperature Range ◽  
Solid State Decomposition ◽  
Ligand Fields

The 2,3- and 3,5-dimethoxybenzoates of Co(II), Ni(II) and Cu(II) were synthesized as solids and their magnetic, spectral and thermal properties studied. The complexes are hydrated or anhydrous compounds which possess colors typical of the M(II) ions. Their thermal stabilities were examined in air and nitrogen and the gaseous and solid state decomposition products were also identified. The magnetic susceptibilities of the complexes were measured over the temperature range 4.4?300 K and the magnetic moments were calculated. The results show that the 2,3- and 3,5-dimethoxybenzoates of Co(II) and Ni(II) are high-spin complexes with weak ligand fields, and that the complexes of Cu(II) form dimers.

MAGNETIC PROPERTIES OF U1-xDyxAlyNi5-y (y=0,1) SYSTEMS

2003 ◽  
Vol 17 (27n28) ◽  
pp. 1453-1460
Author(s):  
ILEANA LUPSA
Keyword(s):  
Magnetic Properties ◽  
Low Temperature ◽  
Spin Fluctuation ◽  
Magnetic Moments ◽  
Transition Temperatures ◽  
Temperature Range ◽  
Fluctuation Model ◽  
Magnetically Ordered

The magnetic properties of U 1-x Dy x Al y Ni 5-y (y=0,1) systems were investigated in the 2(5)–600 K temperature range and for fields up to 80 kOe. The systems having x≥0.2 are magnetically ordered with low transition temperatures and magnetization mainly due to the Dy contribution. The nickel exhibits magnetic moments, very weak in the low temperature range and well-defined effective moments over transition temperatures. The nickel behavior is discussed in terms of the spin fluctuation model.

Thermoanalytical Methods in Vulcanizate Analysis II. Derivative Thermogravimetric Analysis

1975 ◽  
Vol 48 (4) ◽  
pp. 661-677 ◽  
Author(s):  
D. W. Brazier ◽  
G. H. Nickel
Keyword(s):  
Preceding Paper ◽  
Limiting Factor ◽  
Inorganic Pigments ◽  
Thermal Stabilities ◽  
Pyrolysis Products ◽  
Exothermic Reactions ◽  
Temperature Range ◽  
Black Oil ◽  
Scan Rate ◽  
Tg And Dtg

Abstract We have shown in this and the preceding paper that fully compounded stocks can be analyzed for all main constituents by use of a combination of DSC, TG, and DTG. Further, this can be achieved on a time scale consistent with routine quality control. DSC gives information on cure characteristics, sulfur, and accelerator levels in approximately five minutes. Elastomer, elastomer ratio, carbon black, oil/plasticizer, and inorganic pigments are determined in about 35 minutes by TG/DTG, at a scan rate of 10°C/min. This time can be reduced by increasing the scan rate, but interference from highly exothermic reactions can be a limiting factor. Each compound must be treated individually to determine the maximum scan rate that can be used without impairing reproducibility. Clearly limitations exist for identification of unknown blends by DTG. The main problem is that many commercial elastomers have very similar thermal stabilities, which results in DTG peaks in the same temperature range. Further work is being undertaken with the DTG—gas chromatography interface to identify not only the pyrolysis products, but the temperature range over which they are evolved. In this manner, the DTG acts essentially as a thermal fraetionation unit and GC analysis of products from a given component in a blend can be achieved.

Preparation and Properties of Silicon-Containing Arylacetylene Resins with Octa(maleimidophenyl)silsesquioxane

2012 ◽  
Vol 557-559 ◽  
pp. 1152-1156
Author(s):  
Yan Zhou ◽  
Fu Wei Huang ◽  
Fa Rong Huang ◽  
Lei Du
Keyword(s):  
Thermal Stability ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Thermal Polymerization ◽  
Curing Process ◽  
Thermal Stabilities ◽  
Curing Reaction ◽  
Air Atmosphere ◽  
Ft Ir ◽  
Dsc Analyses

Modified silicon-containing arylacetylene resins (DMSEPE-OMPS) were prepared from poly(dimethylsilyleneethynylenephenyleneethynylene) (DMSEPE) and Octa(maleimidophenyl)- silsesquioxane (OMPS). The curing reaction of DMSEPE-OMPS resin was studied by FT-IR and DSC techniques. Thermal stability and dielectric properties of cured DMSEPE-OMPS resins were determined. FT-IR and DSC analyses indicate that thermal polymerization of DMSEPE-OMPS resin occurs in the curing process. Thermal stabilities of cured DMSEPE-OMPS resins under N2 and air atmosphere decrease gradually with the increment of OMPS components. The incorporation of OMPS can obviously reduce dielectric constant of DMSEPE-OMPS resins.

scholarly journals Модель поведения гранулярного ВТСП во внешнем магнитном поле: температурная эволюция гистерезиса магнитосопротивления

2020 ◽  
Vol 62 (7) ◽  
pp. 1008
Author(s):  
С.В. Семенов ◽  
Д.А. Балаев
Keyword(s):  
High Temperature ◽  
External Field ◽  
High Temperature Superconductor ◽  
Magnetic Moments ◽  
Local Maximum ◽  
Effective Field ◽  
Temperature Range ◽  
Flux Compression ◽  
Local Extrema ◽  
Extraordinary Form

Abstract A model for describing the magnetoresistance behavior in a granular high-temperature superconductor (HTS) that has been developed in the last decade explains a fairly extraordinary form of the hysteretic R ( H ) dependences at T = const and their hysteretic features, including the local maximum, the negative magnetoresistance region, and the local minimum. In the framework of this model, the effective field B _eff in the intergrain medium has been considered, which represents a superposition of the external field and the field induced by the magnetic moments of HTS grains. This field can be written in the form B _eff( H ) = H + 4πα M ( H ), where M ( H ) is the experimental field dependence of the magnetization and α is the parameter of crowding of the magnetic induction lines in the intergrain medium. Therefore, the magnetoresistance is a function of not simply an external field, but also the “internal” effective field R ( H ) = f ( B _eff( H )). The magnetoresistance of the granular YBa_2Cu_3O_7 – δ HTS has been investigated in a wide temperature range. The experimental hysteretic R ( H ) dependences obtained in the high -temperature range (77–90 K) are well explained using the developed model and the parameter α is 20–25. However, at a temperature of 4.2 K, no local extrema are observed, although the expression for B _eff( H ) predicts them and the parameter α somewhat increases (~30–35) at this temperature. An additional factor that must be taken into account in this model can be the redistribution of the microscopic current trajectories, which also affects the dissipation in the intergrain medium. At low temperatures under the strong magnetic flux compression (α ~ 30–35), the microscopic trajectories of the current I _ m can change and tunneling through the neighboring grain is preferred, but the angle between I _ m and B _eff will be noticeably smaller than 90°, although the external (and effective) field direction is perpendicular to the macroscopic current direction.

scholarly journals Synthesis and Mesomorphic Properties of Novel Bent-shaped Naphthyl Diketones

2019 ◽  
Vol 92 (2) ◽  
pp. 173-179 ◽  
Author(s):  
Anđela Buljan ◽  
Anamarija Knežević ◽  
Irena Dokli ◽  
Andreja Lesac
Keyword(s):  
Thermal Behaviour ◽  
Nematic Phase ◽  
Liquid Crystalline ◽  
Molecular Packing ◽  
Broad Temperature Range ◽  
Structural Modifications ◽  
Temperature Range ◽  
Mesomorphic Properties

The synthesis and liquid-crystalline properties are reported for novel naphthyl-based diketones incorporating variant terminal chains and lateral fluoro- substitution. Newly prepared materials exhibit a broad temperature range of the nematic phase. The study demonstrates how subtle structural modifications can be exploited to alter the efficiency of molecular packing and consequently the thermal behaviour.

On the Thermal Behaviour of Some Alkali Branched Alkanoates. Note I

1978 ◽  
Vol 33 (2) ◽  
pp. 240-242 ◽  
Author(s):  
P. Ferloni ◽  
M. Sanesi ◽  
P. L. Tonelli ◽  
P. Franzosini
Keyword(s):  
Phase Transition ◽  
Thermal Behaviour ◽  
Differential Scanning Calorimetric ◽  
Transition Temperatures ◽  
Calorimetric Investigation ◽  
Temperature Range ◽  
Heat Effects ◽  
Phase Transition Temperatures ◽  
Sodium And Potassium

Lithium, sodium and potassium isobutyrates, isovalerates and isocaproates were submitted to a differential scanning calorimetric investigation in the temperature range between 320 K and the isotropic melt region. The collected phase transition temperatures and heat effects are compared to those of the corresponding linear isomers. In particular the occurrence of mesomorphic liquids and the width of their existence fields is discussed.

Chemical Synthesis of Pure and Doped LaGaO3 Powders of Oxide Fuel Cells by Amorphous Citrate/EG Method

1999 ◽  
Vol 606 ◽  
Author(s):  
A.C. Tas ◽  
H. Schluckwerder ◽  
P. Majewski ◽  
F. Aldinger
Keyword(s):  
Fuel Cells ◽  
Chemical Synthesis ◽  
Oxide Fuel ◽  
Carbon And Nitrogen ◽  
Temperature Range ◽  
Air Atmosphere ◽  
Precursor Powders

AbstractPowders of LaGaO3, La0.9Sr0.1GaO2.95 and La0.8Sr0.2Ga0.83Mg0.17O2.815 were prepared by the amorphous citrate/EG method. The calcination behavior of the precursor powders of the above phases were studied in the temperature range of 200°-1400°C, in an air atmosphere. Characterization of the samples were performed by XRD, TG/DTA, FTLR, SEM, ICP-AES, and carbon and nitrogen analyses.

Thermal Stability of GaAs/InGaP and InGaP/(In)GaAs Interfaces

1995 ◽  
Vol 405 ◽  
Author(s):  
F. Hyuga ◽  
T. Nittono ◽  
K. Watanabe ◽  
T. Furuta
Keyword(s):  
Thermal Stability ◽  
Quantum Wells ◽  
Annealing Time ◽  
High Performance ◽  
High Reliability ◽  
Half Maximum ◽  
Single Quantum ◽  
Thermal Stabilities ◽  
Temperature Range ◽  
Thermal Stability Of

AbstractThermal stabilities of GaAs/InGaP and InGaP/(In)GaAs interfaces are investigated using InGaP/(In)GaAs/InGaP single quantum wells. Annealing is performed at a temperature range between 600 and 900 °C for 10 min. Positions and the full widths at half maximum (FWHM) of photoluminescence (PL) peaks are almost identical to those of as-grown ones up to 800 °C. Blue shifts of PL peaks and increased widths of their FWHM observed after 900 °C annealing are suppressed by shortening the annealing time to 0.1 sec. Annealing at 900 ‘C for 0.1 sec is sufficient to activate Si ions implanted into (In)GaAs layers. As a result, these thermal stabilities are able to provide high reliability and high performance of InGaP/(In)GaAs heterostructure MESFET ICs.

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