scholarly journals Magnetic mineralogy of Variscan granites from northern Portugal: an approach to their petrogenesis and metallogenic potential

2020 ◽  
Vol 18 ◽  
pp. 1-20
Author(s):  
C. Cruz ◽  
H. Sant'Ovaia ◽  
F. Noronha
Keyword(s):  
Magnetic Susceptibility ◽  
Magnetic Behavior ◽  
Redox Conditions ◽  
Magnetic Mineralogy ◽  
Magma Genesis ◽  
Northern Portugal ◽  
Hydrothermal Deposits ◽  
Variscan Granites ◽  
Redox History

Northern Portugal is characterized by the occurrence of numerous W hydrothermal deposits spatially associated with granites. The primary goal of this work is to establish a relationship between the magnetic behavior of thegranites and the redox conditions during magma genesis, as this can influence the occurrence of mineralizations, namely of W (Mo). To this end, the magnetic mineralogy of the granites of the Lamas de Olo Pluton, a posttectonic pluton in northern Portugal, with associated W (Mo) occurrences was characterized and compared with the magnetic mineralogy of other post-tectonic Variscan plutons. This pluton is composed of different biotite granites: Lamas de Olo, Alto dos Cabeços and Barragem. To better characterize its magnetic behavior, differentanalytical techniques that complement previous magnetic susceptibility studies were performed. The magnetic mineralogy of Lamas de Olo Pluton was then compared with other post-tectonic Variscan plutons such as the Vila Pouca de Aguiar, Peneda-Gerês and Lavadores-Madalena plutons. The presence of magnetite in some of these granites is important because it points to melt-oxidized conditions not commonly found in Iberian Variscan granites. Our study shows that granite areas where magnetite and/or magnetite/ilmenite coexist are important targets for W (Mo) mineralizations. The results indicate that a few plutons have granites with a complex redox history which leads to the formation of magnetite and ilmenite.

scholarly journals Collective Magnetic Behavior of 11 nm Photo-Switchable CsCoFe Prussian Blue Analogue Nanocrystals: Effect of Dilution and Light Intensity

2021 ◽  
Vol 7 (7) ◽  
pp. 99
Author(s):  
Linh Trinh ◽  
Eric Rivière ◽  
Sandra Mazerat ◽  
Laure Catala ◽  
Talal Mallah
Keyword(s):  
Magnetic Susceptibility ◽  
Light Intensity ◽  
Prussian Blue ◽  
Magnetic Behavior ◽  
Magnetic Interaction ◽  
Light Irradiation ◽  
Prussian Blue Analogue ◽  
Magnetic Susceptibility Data ◽  
Susceptibility Data

The collective magnetic behavior of photoswitchable 11 nm cyanide-bridged nanoparticles based of the Prussian blue analogue CsCoFe were investigated when embedded in two different matrices with different concentrations. The effect of the intensity of light irradiation was studied in the less concentrated sample. Magnetization studies and alternating magnetic susceptibility data are consistent with a collective magnetic behavior due to interparticle dipolar magnetic interaction for the two compounds, even though the objects have a size that place them in the superparamagnetic regime.

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.

Hydrothermal synthesis, structure and magnetic properties of a three-dimensional cobalt(ii) – aminophenyltetrazolate coordination polymer

2014 ◽  
Vol 43 (19) ◽  
pp. 7263-7268 ◽  
Author(s):  
Tiffany M. Smith ◽  
Michael Tichenor ◽  
Yuan-Zhu Zhang ◽  
Kim R. Dunbar ◽  
Jon Zubieta
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Hydrothermal Synthesis ◽  
Coordination Polymer ◽  
Three Dimensional ◽  
Magnetic Behavior ◽  
Ac Magnetic Susceptibility

The three-dimensional [Co3(OH)2(H2O)2(aptet)4] exhibits magnetic properties consistent with a ferrimagnetic chain with the non-compensating resultant moment of one Co(ii) per trinuclear Co(ii) subunit and ac magnetic susceptibility indicative of glassy-like magnetic behavior.

On the influence of magnetic mineralogy in the tectonic interpretation of anisotropy of magnetic susceptibility in cataclastic fault zones

2018 ◽  
Vol 216 (2) ◽  
pp. 1043-1061 ◽  
Author(s):  
Teresa Román-Berdiel ◽  
Antonio M Casas-Sainz ◽  
Belén Oliva-Urcia ◽  
Pablo Calvín ◽  
Juan José Villalaín
Keyword(s):  
Magnetic Susceptibility ◽  
Anisotropy Of Magnetic Susceptibility ◽  
Fault Zones ◽  
Magnetic Mineralogy ◽  
Tectonic Interpretation

Twinned olivenite from Cap Garonne, Mine du Pradet – structure and magnetic behavior

2020 ◽  
Vol 235 (1-2) ◽  
pp. 7-13
Author(s):  
Jutta Kösters ◽  
Christian Paulsen ◽  
Frank Stegemann ◽  
Birgit Heying ◽  
Valérie Galéa-Clolus ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Single Crystals ◽  
Cluster Model ◽  
Spin Exchange ◽  
Magnetic Behavior ◽  
Exchange Parameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spin Cluster ◽  
Antiferromagnetic Spin

AbstractSystematically twinned olivenite (Cu2(AsO4)OH) single crystals from Cap Garonne, Mine du Pradet, France, were studied by X-ray diffraction: P 21/n, a = 822.69(6) pm, b = 861.88(9) pm, c = 594.06(9) pm, β = 90.000(6)°, wR = 0.0224, 1621 F2 values, 79 variables and a domain ratio of 0.501(1)/0.499(1). The temperature dependence of the magnetic susceptibility was well reproduced with a square-spin cluster model and an antiferromagnetic spin-exchange parameter of J/kB = 157(3) K.

Observation of magnetic behavior with two broad maxima of magnetic susceptibility in [Ni(mnt)2]− complexes

2010 ◽  
Vol 968 (1-3) ◽  
pp. 67-75
Author(s):  
Fang Xuan ◽  
Zheng-Fang Tian ◽  
Xiao-Ming Ren ◽  
Hai-Bao Duan ◽  
Qing-Jin Meng
Keyword(s):  
Magnetic Susceptibility ◽  
Magnetic Behavior

The Effect of Partial Substitution of Non-Magnetic Impurity Zn on the Magnetic Moments of Eu1.88Ce0.12Cu1-yZnyO4+α-δ

2021 ◽  
Vol 1028 ◽  
pp. 15-20
Author(s):  
Muhammad Abdan Syakuur ◽  
Yati Maryati ◽  
Togar Saragi ◽  
Risdiana
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Magnetic Impurity ◽  
Magnetic Moments ◽  
Magnetic Behavior ◽  
Partial Substitution ◽  
X Ray Diffraction ◽  
Magnetic Susceptibility Data ◽  
Susceptibility Data ◽  
Volume Unit

Structure and magnetic properties of electron-doped superconducting cuprates have been investigated in order to study the effect of magnetic impurity to its physical properties. Here, we reported structure and magnetic properties of Eu1.88Ce0.12Cu1-yZnyO4+α-δ (ECCZO) with y = 0 and 0.03. The properties of ECCZO have been studied from X-ray diffraction data and temperature dependence of magnetic susceptibility data, to elucidate the effect of partial substitution of non-magnetic impurity Zn for Cu to its structure, Tc and the value of magnetic moments per unit volume extracted from susceptibility data in normal state. Magnetic-susceptibility measurements were carried out down to 2 K on-field cooling at 5 Oe for Eu1.88Ce0.12Cu1-yZnyO4+a-d with y = 0 and 0.03. For ECCZO sample with y = 0 and d = 0.0669 indicated the change of magnetic behavior from paramagnetic to diamagnetic below 12 K which is addressed to the Tc onset of this samples. Diamagnetic behavior is observed starting from about 12 K. Above 12 K, all samples show paramagnetic behavior with the values of the magnetic moment in every volume unit increased with increasing Zn.

Magnetic properties of soils in a designated Natura area (GR4310010, Giouchtas Mountain)

2015 ◽  
Vol 3 (4) ◽  
pp. SAB33-SAB42 ◽  
Author(s):  
Eleni Kokinou
Keyword(s):  
Magnetic Susceptibility ◽  
Surface Soil ◽  
Magnetic Behavior ◽  
High Elevation ◽  
Soil Samples ◽  
Tectonic Activity ◽  
Anthropogenic Factors ◽  
Recent Sediments ◽  
Available Information ◽  
Natural And Anthropogenic Factors

The magnetic behavior of the geologic formations around the Giouchtas or Juchtas Mountain (Mt.) in Central Crete, Greece, has been studied. The magnetic parameters (magnetic susceptibility [MS] and temperature dependence of the magnetic susceptibility) of 160 surface soil samples were interpreted based on available information (e.g., topographic, geologic, and historical) for the area of study. The soil samples have been collected from the low- and high-elevation regions of Giouchtas Mt. The low-elevation region, surrounding a north–south asymmetric ridge (strongly affected by the tectonic activity), is mainly covered by Miocene and recent sediments, whereas the high-elevation region is dominated by limestones. Differences in the spatial distribution of the MS and the thermomagnetic behavior of the soil samples indicated the strong influence of natural and anthropogenic factors on the geologic formations.

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.

The magnetic properties of natural pigments: preliminary analyses for their identification in Fine Arts

2021 ◽  
Author(s):  
Chiara Anselmi ◽  
Antonio Sgamellotti ◽  
Manuela Vagnini ◽  
Aldo Winkler
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Magnetic Measurements ◽  
Rock Magnetism ◽  
Fine Arts ◽  
Magnetic Behavior ◽  
Spectroscopic Techniques ◽  
Magnetic Carriers ◽  
Magnetic Techniques ◽  
Synthetic Pigments

&lt;p&gt;A multidisciplinary approach, including compositional, spectroscopic and microscopic methodologies, is often used for the analysis and identification of pigments in Fine Arts. Although a large part of widely used natural and synthetic pigments contain Fe-oxides and hydroxides, their magnetic characterization is still poorly explored. The application of rock magnetism analyses through fast, cheap and non-destructive measurements, can be instead useful for the identification and discrimination of pigments through their distinctive magnetic properties.&lt;/p&gt;&lt;p&gt;In this preliminary study, the magnetic properties of several iron-based commercial pigments together with paintings models and supports, were analyzed.&lt;/p&gt;&lt;p&gt;In order to investigate the compositional differences of pigments by means of their magnetic behavior, the magnetic susceptibility, the hysteresis properties and the magnetic susceptibility variation at low and high temperature were measured on selected samples.&lt;/p&gt;&lt;p&gt;All the pigments showed different magnetic properties, mainly related to variable proportions of magnetite, hematite and maghemite as the main magnetic carriers.&lt;/p&gt;&lt;p&gt;Further studies will be addressed to define a protocol for applying the magnetic techniques to the characterization of pigments, including tests on samples produced by different brands and different periods, with the final aim of integrating the magnetic measurements with the different spectroscopic techniques commonly employed for the preservation and the analysis of cultural heritage.&lt;/p&gt;

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