The complexes of iminodiacetic acid with divalent manganese and iron

1982 ◽  
Vol 47 (4) ◽  
pp. 1169-1175 ◽  
Author(s):  
Ivan Lukeš ◽  
Ivana Šmídová ◽  
Miroslav Ebert
Keyword(s):  
Thermal Stability ◽  
Magnetic Properties ◽  
Solid State ◽  
High Spin ◽  
Infrared Spectra ◽  
Iminodiacetic Acid ◽  
Octahedral Configuration

Complexes of the type M2[Me(IDA)2] and MeIDA.n H2O, where M = H+, Li+, Na+, K+, 1/2 Ba2+, Me = Mn2+, Fe2+ and IDA = [NH(CH2COO)2]2- were prepared in the solid state. The magnetic properties, thermal stability and electron and infrared spectra of these substances were studied. It followed from the results that both prepared types of complex have a high spin octahedral configuration. In contrast to M2[Me(IDA)2] type complexes, complexes of the Me IDA . nH2O type have polymeric character.

Metal-Complexes of 1,10-Phenanthroline Derivatives. XV. Complexes of 2-(3,5-Dimethylpyrazol-1-yl)-1,10-phenanthroline

1988 ◽  
Vol 41 (6) ◽  
pp. 873 ◽  
Author(s):  
AS Abushamleh ◽  
HA Goodwin
Keyword(s):  
Magnetic Properties ◽  
Solid State ◽  
Spectral Data ◽  
High Spin ◽  
Nickel Complex ◽  
Spin Transition ◽  
Critical Value ◽  
Magnetic Data ◽  
Strong Temperature Dependence ◽  
Thermally Induced

Iron(II) and nickel(II) bis ( ligand ) complexes of 2-(3,5-dimethylpyrazol-1-yl)-1,10-phenanthroline (L) have been prepared. The field strength of L as determined from spectral data for the nickel complex is in the range encompassing the critical value at the singlet (1A1) ↔ quintet (5T2) crossover for iron(II). The magnetic properties of the iron(II) complex both in solution and in the solid state are anomalous, and indicative of the occurrence of a thermally induced spin transition. Mossbauer spectral data confirm this, and reveal separate contributions from the singlet and quintet species with a strong temperature-dependence of their relative intensities. Magnetic data for the complex in solution are consistent with a simple high spin ↔ low spin equilibrium, and lead to values of ΔH = 23�0.5 kJ mol-1 and ΔS = 66�5 J K-1 mol-1 for the low spin → high spin transformation.

Thermal instability of Co-substituted barium hexaferrites with U-type structure

2006 ◽  
Vol 21 (2) ◽  
pp. 420-427 ◽  
Author(s):  
Darja Lisjak ◽  
Paul McGuiness ◽  
Miha Drofenik
Keyword(s):  
Thermal Stability ◽  
Magnetic Properties ◽  
Solid State ◽  
Thermal Instability ◽  
High Energy ◽  
Type Structure ◽  
Stability Studies ◽  
X Ray ◽  
Barium Hexaferrites ◽  
Annealing Conditions

Thermal stability studies of Co-substituted barium hexaferrites with the U-type structure are reported. Samples were prepared using solid-state reaction and high-energy milling at 1300 and 1250 °C, respectively. The influence of different annealing conditions on their compositions and magnetic properties was studied. Thermal instability of the studied compounds was observed at as low as 600 °C. Through x-ray powder diffraction, chemical analysis, and thermomagnetic measurements it was confirmed that a degradation of the U-hexaferrites occurred during the annealing at 600–800 °C. The observed changes in the samples’ phase compositions and structures did not have a significant influence on their magnetization and microwave properties.

Time and thermal stability of magnetic properties of amorphous Fe80TM3B17 alloys

1998 ◽  
Vol 08 (PR2) ◽  
pp. Pr2-63-Pr2-66 ◽  
Author(s):  
R. Varga ◽  
P. Vojtaník ◽  
A. Lovas
Keyword(s):  
Thermal Stability ◽  
Magnetic Properties ◽  
Thermal Stability Of

X-ray Structure Refinement and Vibrational Spectroscopy of Ca8Gd2 (PO4)6 O2

2013 ◽  
Vol 12 (10) ◽  
pp. 719-726
Author(s):  
R. Ayadi ◽  
Mohamed Boujelbene ◽  
T. Mhiri
Keyword(s):  
Solid State ◽  
General Formula ◽  
Vibrational Spectroscopy ◽  
Powder Diffraction ◽  
Infrared Spectra ◽  
Solid State Reaction ◽  
Structure Refinement ◽  
Unit Cell ◽  
Cell Group ◽  
X Ray

The present paper is interested in the study of compounds from the apatite family with the general formula Ca10 (PO4)6A2. It particularly brings to light the exploitation of the distinctive stereochemistries of two Ca positions in apatite. In fact, Gd-Bearing oxyapatiteCa8 Gd2 (PO4)6O2 has been synthesized by solid state reaction and characterized by X-ray powder diffraction. The site occupancies of substituents is0.3333 in Gd and 0.3333 for Ca in the Ca(1) position and 0. 5 for Gd in the Ca (2) position.  Besides, the observed frequencies in the Raman and infrared spectra were explained and discussed on the basis of unit-cell group analyses.

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