EPR and magnetic susceptibility studies of iron ions in 70TeO2·25B2O3·5PbO glass matrix

1997 ◽  
Vol 102 (4) ◽  
pp. 341-346 ◽  
Author(s):  
I. Ardelean ◽  
M. Peteanu ◽  
S. Filip ◽  
V. Simon ◽  
G. Györffy
Keyword(s):  
Magnetic Susceptibility ◽  
Glass Matrix ◽  
Iron Ions

MAGNETIC BEHAVIOR OF IRON IONS IN THE P2O5·CaO GLASS MATRIX

2003 ◽  
Vol 17 (24) ◽  
pp. 1271-1275 ◽  
Author(s):  
I. ARDELEAN ◽  
C. ANDRONACHE ◽  
P. PǍŞCUŢǍ
Keyword(s):  
Magnetic Susceptibility ◽  
High Temperature ◽  
Magnetic Moment ◽  
Glass Matrix ◽  
Magnetic Behavior ◽  
Iron Ions ◽  
Ion Content ◽  
Dipole Interactions ◽  
Valence States ◽  
Temperature Susceptibility

The temperature dependence of the magnetic susceptibility of x Fe 2 O 3·(100-x)-[ P 2 O 5· CaO ] glasses with 0<x≤50 mol % have been investigated. These data revealed that the valence states and the distribution of iron ions in the glass matrix depend on the Fe 2 O 3 content. For the glasses with x≤1 mol % only Fe 3+ ions are evidenced. In the case of the glasses with 3≤x≤35 mol % both Fe 3+ and Fe 2 ions co-exist in the P 2 O 5· CaO glass matrix, the Fe 2+ ion content is higher than that of the Fe 3+ ions for glasses with x≥10 mol %. For the glasses with x>35 mol %, the evaluated values of the μ eff indicate either the presence of Fe + ions or the coordination influence on the magnetic moment of iron ions, but the presence of small quantities of the antiferromagnetic or ferrimagnetic interactions between iron ions in studied temperature range cannot be excluded. The high temperature susceptibility results indicate that the iron ions are isolated or participate in dipole-dipole interactions for glasses with x≤35 mol % and are antiferromagnetically coupled for higher contents of Fe 2 O 3.

IRON OXIDATION STATES AND DISTRIBUTION IN THE 4Bi2O3· PbO GLASS MATRIX

2002 ◽  
Vol 16 (01n02) ◽  
pp. 41-46 ◽  
Author(s):  
V. SIMON ◽  
R. POP ◽  
M. NEUMANN ◽  
S. G. CHIUZBAIAN ◽  
M. COLDEA ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Valence State ◽  
Glass Matrix ◽  
Iron Oxidation ◽  
Oxidation States ◽  
Iron Ions ◽  
Metallic Elements ◽  
Iron Oxidation States

Magnetic susceptibility and XPS results on x Fe 2O3 · (100-x) [4 Bi 2O3 · PbO] where 0<x ≤20 samples are presented in order to point out the oxidation states and the distribution of iron ions in the lead-bismuthate matrix. The valence state of iron ions changes from Fe3+ to Fe2+ as the Fe2O3 content increases from 1 to 20 mol%. The XPS data indicate the migration of metallic elements in the inner part of the bulk investigated samples.

EPR AND MAGNETIC SUSCEPTIBILITY STUDIES OF IRON IONS IN THE 3B2O3·KF GLASS MATRIX

2004 ◽  
Vol 18 (10n11) ◽  
pp. 1525-1535 ◽  
Author(s):  
I. ARDELEAN ◽  
P. PASCUTA
Keyword(s):  
Magnetic Susceptibility ◽  
Iron Content ◽  
Glass Matrix ◽  
Structural Changes ◽  
Magnetic Measurement ◽  
Measurement Data ◽  
Ionic Species ◽  
Iron Ions ◽  
Simultaneous Presence ◽  
Valence States

Glasses of the x Fe 2 O 3·(100–x)[3 B 2 O 3· KF ] system, with 0<x≤35 mol %, were investigated by means of EPR and magnetic susceptibility measurements. When increasing the iron content the EPR absorption spectra undergo modification reflecting structural changes of the glass matrix and also the distribution and valence states of iron ions. The magnetic measurement data pointed out the character of interaction involving iron ions as depending on concentration and the simultaneous presence of both Fe 3+ and Fe 2+ ionic species.

MAGNETIC BEHAVIOR OF LEAD-BISMUTATE GLASSES CONTAINING TRANSITION METAL ELEMENTS

2001 ◽  
Vol 15 (27) ◽  
pp. 1231-1236 ◽  
Author(s):  
R. POP ◽  
V. SIMON ◽  
I. COSMA ◽  
M. COLDEA
Keyword(s):  
Experimental Data ◽  
Magnetic Susceptibility ◽  
Transition Metal ◽  
Transition Metal Oxides ◽  
Glass Matrix ◽  
Magnetic Behavior ◽  
Magnetic Interaction ◽  
Iron Ions ◽  
Manganese Ions ◽  
Curie Temperatures

The investigated samples are obtained by adding to the 3Bi2O3·2PbO glass matrix the transition metal oxides Fe2O3 or MnO up to 20 mol%. The temperature dependencies of the magnetic susceptibility evidence negative paramagnetic Curie temperatures suggesting the antiferromagnetic nature of the magnetic interaction between the transition metal (TM) ions in the samples studied. According to the magnetic moment values, calculated from the experimental data, the valence state of the iron ions changes from Fe 3+ to Fe 2+ and that of manganese ions from Mn 2+ to Mn 3+ as the concentration x increases from 1 to 20 mol%.

EPR and Magnetic Susceptibility Studies of Iron Ions in 3B2O3·CaCl2 Glass Matrix

2003 ◽  
Vol 17 (21) ◽  
pp. 3889-3897 ◽  
Author(s):  
I. Ardelean ◽  
P. Păşcuţă
Keyword(s):  
Magnetic Susceptibility ◽  
Glass Matrix ◽  
Iron Ions ◽  
Structural Units ◽  
Valence States

Glass matrix 3B 2 O 3· CaCl 2 doped with iron ions up to 50 mol% were obtained and investigated by means of EPR and magnetic susceptibility. Information concerning the structural units involving iron ions, valence states and the type of the interactions between these ions were discussed.

EPR AND MAGNETIC SUSCEPTIBILITY STUDIES OF COPPER IONS IN THE 2B2O3·Ag2O GLASS MATRIX

2004 ◽  
Vol 18 (20n21) ◽  
pp. 2915-2921 ◽  
Author(s):  
R. CICEO LUCACEL ◽  
I. ARDELEAN
Keyword(s):  
Magnetic Susceptibility ◽  
Glass Matrix ◽  
Magnetic Measurements ◽  
Copper Ions ◽  
Gradual Increase ◽  
Glass Structure ◽  
Ionic Species ◽  
Magnetic Interactions ◽  
Simultaneous Presence ◽  
Distorted Octahedral

Glasses of the x CuO ·(100-x)[2 B 2 O 3· Ag 2 O ] system, with 0<x≤30 mol %, were investigated by means of EPR and magnetic susceptibility measurements. The influence of a gradual increase in CuO content on the glass structure and magnetic interactions that involved copper ions, have been discussed. EPR absorption spectra show Cu 2+ ions in axially distorted octahedral environments. Both EPR and magnetic measurements data pointed out the simultaneous presence in the glasses with x>5 mol % of Cu 2+ and Cu + ionic species. The Curie behavior of magnetic susceptibility indicates the absence of the superexchange interactions in these glasses.

EPR AND MAGNETIC SUSCEPTIBILITY STUDIES OF CALCIUM-BORATE OXIDE GLASSES CONTAINING IRON IONS

2002 ◽  
Vol 16 (07) ◽  
pp. 231-239 ◽  
Author(s):  
I. ARDELEAN ◽  
P. PASCUTA ◽  
M. PETEANU
Keyword(s):  
Magnetic Susceptibility ◽  
Iron Content ◽  
Exchange Interactions ◽  
Ionic Species ◽  
Iron Ions ◽  
Oxide Glasses ◽  
Calcium Borate ◽  
Octahedral Symmetry ◽  
Distorted Octahedral ◽  
Borate Oxide

EPR and magnetic susceptibility measurements have been performed on x Fe 2 O 3·(100-x) [3B2O3·CaO] glasses with 0<x≤40 mol%. The Fe 3+ ions in sites of distorted octahedral symmetry and clustered formations containing both Fe 3+ and Fe 2+ ionic species were found. Dipolar and magnetic super-exchange interactions involving iron ions were revealed to depend on the iron content of the sample.

THE INFLUENCE OF MELTING TEMPERATURE ON IRON ION DISTRIBUTION IN Bi2O3·PbO·As2O3 GLASS MATRIX STUDIED BY EPR

2000 ◽  
Vol 14 (22n23) ◽  
pp. 785-790 ◽  
Author(s):  
I. ARDELEAN ◽  
M. PETEANU ◽  
V. SIMON ◽  
C. BORSA ◽  
F. CIORCAS ◽  
...  
Keyword(s):  
Melting Temperature ◽  
Valence State ◽  
Glass Matrix ◽  
Composition Range ◽  
Iron Ions ◽  
Iron Ion ◽  
Ion Distribution ◽  
Structural Distribution

Glasses of the system x Fe2O3·(1-x)[Bi2O3·P b O· As 2O3] in the composition range 0.5≤x≤30 mol% were investigated when prepared at 1000°C and 1250°C, respectively. The study was performed by means of EPR of Fe3+ ions. The effects of melting temperature on the valence state and structural distribution of iron ions were shown.

MAGNETIC BEHAVIOR OF SAMARIUM IONS IN 2B2O3 · PbO GLASS MATRIX

2002 ◽  
Vol 16 (20) ◽  
pp. 757-760
Author(s):  
I. ARDELEAN
Keyword(s):  
Magnetic Susceptibility ◽  
Glass Matrix ◽  
Magnetic Behavior ◽  
Van Vleck

Magnetic susceptibility measurements were performed on x Sm 2 O 3 · (100 - x)[ 2B 2 O 3 · PbO ] glasses with x ≤ 40 mol %. These data were analyzed using the Van Vleck model for magnetic behavior of free Sm 3+ ions.

Synthesis, Crystal Structure, and Spectroscopic and Magnetic Properties of a Dinuclear Iron(III) Complex Asymmetrically Bridged by a Phenoxo and a Methoxo Group

2005 ◽  
Vol 60 (9) ◽  
pp. 940-944 ◽  
Author(s):  
C. T. Zeyrek ◽  
A. Elmali ◽  
Y. Elerman
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Structural Parameters ◽  
Hamiltonian Operator ◽  
Antiferromagnetic Coupling ◽  
Iron Ions ◽  
Spin Hamiltonian ◽  
Dinuclear Iron ◽  
Super Exchange Interaction

A new dinuclear iron(III) derivative Fe2L(OCH3)Cl2 (L = 1,3-bis[N-(5-chloro-2-hydroxybenzylidene)- 2-aminoethyl]-2-(5-chloro-2-hydroxyphenyl)imidazolidine) has been synthesized, it crystal structure determined and magnetically characterized. The two iron(III) ions are asymmetrically bridged by a phenoxo and a methoxo group and separated by 3.150(2)Å . The magnetic susceptibility of the complex was measured over the range 5 - 349.3 K and the observed data were successfully simulated by the equation based on the spin-Hamiltonian operator , indicating very weak antiferromagnetic coupling between the iron ions with J = −11.3 cm−1. The magnetic and structural parameters of the compound and the nature of the magnetic super-exchange interaction are discussed and compared with data of similar dinuclear iron(III) complexes.

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