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.

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.

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.

Structural and Magnetic Investigations of Fe2O3-B2O3-CaF2 Glass System

2003 ◽  
Vol 17 (13) ◽  
pp. 2633-2641 ◽  
Author(s):  
I. Ardelean ◽  
P. Pǎşcuţǎ ◽  
V. Ioncu
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Mixed Oxide ◽  
Glass System ◽  
Iron Ions ◽  
Structural Units ◽  
Valence States ◽  
Structural And Magnetic Properties

The structural and magnetic properties of a mixed oxide-fluoride vitreous matrix 3B 2 O 3· CaF 2 containing iron ions were investigated. Information concerning the structural units involving iron ions, their valence states and the type of interactions between them were obtained using EPR and magnetic susceptibility measurements.

EPR AND MAGNETIC SUSCEPTIBILITY STUDIES OF B2O3–SrO–Fe2O3 GLASSES

1999 ◽  
Vol 13 (22n23) ◽  
pp. 801-808 ◽  
Author(s):  
I. ARDELEAN ◽  
G. SALVAN ◽  
M. PETEANU ◽  
V. SIMON ◽  
C. HIMCINSCHI ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Iron Ions ◽  
Structural Units ◽  
Paramagnetic Resonance ◽  
Valence States ◽  
Structural And Magnetic Properties ◽  
Electron Paramagnetic ◽  
Controlled Doping

Structural and magnetic properties of B 2 O 3– SrO – Fe 2 O 3 glasses were explored by a controlled doping of 2B 2 O 3· SrO vitreous matrix with iron oxide. The information concerning the structural units involving iron ions, their valence states and the types of interactions between them, was obtained using electron paramagnetic resonance (EPR) spectroscopy and magnetic susceptibility measurements.

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.

THE STRUCTURAL STUDY OF Fe2O3–TeO2–B2O3–SrF2 GLASSES BY EPR AND IR SPECTROSCOPIES

2000 ◽  
Vol 14 (17n18) ◽  
pp. 653-661 ◽  
Author(s):  
I. ARDELEAN ◽  
F. CIORCAS ◽  
M. PETEANU ◽  
I. BRATU ◽  
V. IONCU
Keyword(s):  
Structural Changes ◽  
Mixed Valence ◽  
Ir Absorption ◽  
Iron Ions ◽  
Structural Units ◽  
Spectra Analysis ◽  
Valence States ◽  
Ir Absorption Spectra ◽  
Distorted Octahedral ◽  
Paramagnetic Ions

The local structure of Fe2O3–TeO2–B2O3–SrF2 glasses was studied by recording the EPR and IR absorption spectra. Structural changes and increasing glass stability were evidenced with the addition of Fe2O3 in the sample. The distribution of isolated paramagnetic ions in sites of strongly distorted octahedral symmetry was detected at low concentration (up to 3 mol% Fe2O3) by means of EPR measurements. For x>3 mol% Fe2O3, the clustered iron ions become progressively preponderent in the system. Mixed valence states of iron ions involved in dipole–dipole and superexchange type interactions were also evidenced. The IR spectra analysis revealed the BO3, BO4 and B2O6 units in the structure of tellurite investigated glasses. Among these structural units, those containing the threefold boron atoms are predominant.

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 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

Nonlinear physical properties of some nonconventional semiconducting Bi–Pb–Ba–O glasses

1998 ◽  
Vol 13 (8) ◽  
pp. 2328-2333
Author(s):  
D. K. Modak ◽  
G. Banerjee ◽  
M. Karar ◽  
M. Sadhukhan ◽  
A. K. Bera ◽  
...  
Keyword(s):  
Glass Matrix ◽  
Glass Network ◽  
Nonlinear Behavior ◽  
Local Instability ◽  
Temperature Dependent ◽  
Structural Units ◽  
Local Ordering ◽  
Fast Quenching ◽  
Heat Capacity Anomaly ◽  
Glass Compositions

Semiconducting Bi1−xPbxBaO3−δ (or BPB) glasses with x = 0 to 0.8 have been prepared by fast quenching from the melt. Interesting anomalies in the temperature-dependent polaronic conductivity and dielectric constant have been observed in all these glass compositions at temperatures, Tp, varying from 310 to 330 K (depending on Pb concentration). This nonlinear behavior is considered to be associated with the local ordering or the displacements of the BiO3 type pyramidal structural units present in the glass matrix (observed from the infrared spectra of these glasses). This type of ordering/displacement gives rise to a local instability in the glass network structure which is also supported by the observed heat capacity anomaly around the same temperatures Tp.

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.

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