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.

scholarly journals Magnetic, thermal and spectroscopic properties of lanthanide(III) 2-(4-chlorophenoxy) acetates, Ln(C8H6ClO3)3•nH2O

2013 ◽  
Vol 78 (9) ◽  
pp. 1335-1349 ◽  
Author(s):  
Wiesława Ferenc ◽  
Beata Cristóvão ◽  
Jan Sarzyński
Keyword(s):  
Magnetic Moments ◽  
Intermediate Formation ◽  
Spectroscopic Properties ◽  
Ligand Field ◽  
X Ray Diffraction ◽  
Magnetic Susceptibilities ◽  
X Ray ◽  
Gaseous Products ◽  
Carboxylate Groups ◽  
Thermogravimetric Studies

4-Chlorophenoxyacetates of lanthanides(III) were synthesized as polycrystalline hydrated solids with the general formulae: Ln(C8H6ClO3)3?2H2O (Ln = La(III), Pr(III), Sm(III), Eu(III) and Tb(III)), Ln(C8H6ClO3)3?H2O (Ln = Dy(III)) and Ln(C8H6ClO3)3?3H2O (Ln = Er(III), Tm(III), Yb(III) and Lu(III) and characterized by elemental analysis, FTIR spectroscopy, magnetic and thermogravimetric studies and also by X-ray diffraction (XRD) measurements. The complexes have colours typical for lanthanide(III) ions. The carboxylate groups bind as bidentate chelating. On heating to 1273 K in air the complexes decompose in three steps. At first they dehydrate in one stage to form anhydrous salts that next decompose to the oxides of respective metals with the intermediate formation of their oxychlorides. The gaseous products of compound thermal decomposition in nitrogen were also determined and the magnetic susceptibilities were measured over the ranges 76-303K and 1.8-303K, and their magnetic moments were calculated. The results show that 4-chlorophenoxyacetates of lanthanides(III) are high-spin complexes with weak ligand field.

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.

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.

Thermal properties of poly(vinilidene fluoride) in the temperature range from 25 to 210 °C

2008 ◽  
Vol 27 (2) ◽  
pp. 204-208 ◽  
Author(s):  
W.N. dos Santos ◽  
C.Y. Iguchi ◽  
R. Gregorio
Keyword(s):  
Thermal Properties ◽  
Temperature Range

The magnetic properties of some complexes of higher-valent manganese

1967 ◽  
Vol 20 (4) ◽  
pp. 629 ◽  
Author(s):  
HA Goodwin ◽  
RN Sylva
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibilities ◽  
Temperature Range

The magnetic susceptibilities of the compounds [bipy-H2][MnCl5], [phen- H2]-[MnCl5], [MnCl3(H2O)bipy], [MnCl3(H2O)phen], [MnF3(H2O)phen], [MnCl3 trpy], [MnCl4 bipy], [MnCl3 bipy], [MnCl3 phen], and [MnO phen2](ClO4)2,0.5H2O have been determined over the temperature range c. 100-300�K. All compounds appeared to follow a Curie-Weiss law. The Curie-Weiss θ values indicate that the first seven compounds are simple paramagnetics, while the last three are antiferromagnetics. The antiferromagnetic behaviour of these compounds indicates that they have bridged structures.

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.

Measurement of the thermal properties of Li2CO3, Na2CO3, K2CO3, CaCO3, MgCO3, and NiCO3 in the temperature range 300-700 K by the heat-flash technique

1995 ◽  
Vol 27/28 (1) ◽  
pp. 41-45
Author(s):  
Abdelsalam Abousehly ◽  
Mohamed Ibrahiem ◽  
Mohamed Desouky ◽  
Afaf Abdel-Rahman ◽  
Mohamed Tag-Alden ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Temperature Range ◽  
Flash Technique
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