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In this work, a detailed analysis of the magnetic composition of the upper meter of sediment from a core from Laguito del Morro, Northern Patagonia, Argentina, was carried out. Measurements of low-frequency magnetic susceptibility, anhysteric remanent magnetization, isothermal remanent magnetization curves (at room temperature), and determination of Curie temperatures were used. Remanence coercivity and different interparametric ratios were calculated. The values obtained for remanence coercivity allowed us to determine three magneto-zones with well-differentiated magnetic mineralogies. The ratio between the isothermal remanent magnetization at -100mT and the saturation magnetization only showed a behavior mirrored by the coercivity in zones I and II. The analysis of the curves at room temperature and the thermal experiments identified magnetite, titanomagnetite, and titanohematite, with magnetite being the main component. The identified zones range from 0 to 16 cm (present - 1890 CE)) for zone I, 16 to 66 cm (1890 - 1570 CE) for zone II and 66 to 100 cm (1260 - 1520 CE) for zone III. Particularly, zone II is framed within the so-called Little Ice Age, so it is expected that the mineralogical variations observed will have a strong climatic component as a cause of the change. [ABSTRACT FROM AUTHOR]

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Agricultural burning is a common practice in sugarcane plantations in Mexico that exerts positive and negative effects on the soil. However, there is no consensus on the soil changes caused by the burning, thus highlighting the need to study this phenomenon through low-cost and quick-toanalyze indicators. Magnetic and color techniques can be indirect, fast, and cheap methods that can help to understand the chemical changes that agricultural burning causes to soils. We aim to evaluate the color and magnetic susceptibility of the soil as indicators of changes caused by agricultural burning. The study was carried out on a Vertisol grown with sugarcane in Tabasco, Mexico. Soil samples were taken at ten sites within the plot, at each site soil samples were collected every two centimeters up to 20 cm of soil depth, before and after agricultural burning. In total, 200 soil samples were analyzed. Temperatures were recorded during agricultural burning at 0, 2, and 5 cm depths. The parameters and color indices were analyzed in the CIE-L*a*b* system in the soil samples, and the high and low-frequency magnetic susceptibility were measured with Bartington MS2 equipment. After agricultural burning, the soils showed increased dark tones at four centimeters depth. Also, magnetic parameters showed changes in soil for the 4 cm in depth after the agricultural burning. The results show that color and magnetic susceptibility are efficient soil properties for identifying soil modifications caused by agricultural burning. In this case study, the effect of agricultural burning on sugarcane crops was short-term and shallow in the soil. [ABSTRACT FROM AUTHOR]

Copyright of Boletin de Geologia is the property of Universidad Industrial de Santander and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A combined magnetic and geochemical analysis was carried out to identify the relationship between magnetic parameters, concentration of major elements and heavy metals in urban dust of Mexico City. Here, we propose simple mathematical models that can estimate the concentration of elements in urban dust by means of magnetic parameters, as well as establish the degree of precision of each model. Magnetic threshold values are also proposed to identify samples with low, medium and high concentrations of elements. Urban dust from Mexico City showed a different concentration of essentially ferrimagnetic minerals and superparamagnetic particles. The concentration of the elements in the urban dust samples were: Al between 3,325 to 27,336 mg kg-1; Cr between 17 to 117 mg kg-1; Cu between 15 to 405 mg kg-1; Fe between 653 to 39,217 mg kg-1; Ni between 21 to 66 mg kg-1; Pb between 27 to 366 mg kg-1; V between 11 to 52 mg kg-1 and Zn between 102 to 537 mg kg-1. The relationship between magnetic parameters and concentration of element is rather linear, showing positive Pearson correlation coefficients with values between 0.26 to 0.69. Magnetic threshold values were proposed to identify sites with relatively high accumulation of Cr, Cu, Ni, Pb and Zn. These values for specific magnetic susceptibility are: Low < 2.86 µm3 kg-1; Moderate: 2.86 to 3.46 µm3 kg-1 and High > 3.46 µm3 kg-1; and for remanent isothermal magnetization of saturation: Low < 38 mAm2 kg-1; Moderate: between 38 to 46 mAm2 kg-1 and High > 46 mAm2 kg-1. Mathematical models to estimate the concentration of elements showed effectiveness of about 60%. [ABSTRACT FROM AUTHOR]

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Monitoring and control of the microbiological quality of the air is very important for human activity, which is why aeromicrobiology has boomed in recent years. Specialists suggest that to study the airborne of indoor and outdoor environments, numerous factors must be taken into account such as temperature, relative humidity, the time of year and even the time of the study, however, they forget that microorganisms are charged bioparticles and ignore the presence of an extremely low frequency oscillating magnetic field (ELF-OMF) at the time of air sampling. For this reason, the aim of this paper was to analyze the bibliographic sources that support the considerations about the influence of the ELF-OMF on the indoor airborne of indoor environments. The accepted scientific knowledge in microbiology on the effect of ionizing radiation on the excretion of pigments by the fungi and the electrical charge of microorganisms was linked to the experimental results of the electromagnetic attraction suffered by the same and the dust particles and ions in the air to which they may be united. Based on the link made, was supported that the ELF-OMF influences on the indoor indoor airborne, so it should be seen as a physical factor for the microbiological samplings of indoor air. [ABSTRACT FROM AUTHOR]

The purpose of this study is to contribute to the petrophysical generalization performance of Bahía Honda region for mineral exploration purposes. For this purpose, the lithotypes present in the region were characterized, based on the existing magnetic, gravimetric and radiometric surveys, at a scale of 1: 100,000, as well as the values of density, magnetic susceptibility and gamma intensity measured in a significant number of pits. Statistical processing of aforementioned physical properties assisted the Petrophysical characterization. Linking physical properties with existing geophysical surveys allowed obtaining maps of spatial performance of these properties, not only for the lithotypes described, but also in the geological formations present in the area, which constitutes an important tool for mapping work, geological and mining prospecting carried out in the region. [ABSTRACT FROM AUTHOR]

Copyright of Revista de la Sociedad Química del Perú is the property of Sociedad Quimica del Peru and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales is the property of Academia Colombiana de Ciencias Exactas, Fisicas y Naturales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to verify if the magnetic parameters can be indicators of soil contamination, the relationship between magnetic parameters and the concentration of heavy metals in soil samples from the Almendares-Vento basin was studied. Measurements of magnetic susceptibility, chemical determinations of heavy elements and remanent magnetization, were made. The concentration values in the samples of the heavy elements (Cr, Fe, Ni, Mn, Cu, Zn and Pb) were determined by mass spectrometry with inductively coupled plasma. Magnetic susceptibility yielded higher values towards the upper part of the soil, up to 20 cm deep, which can be attributed to the presence of magnetic material of anthropogenic origin on the soil surface, generated by productive processes at the facilities of the region. It is concluded that increases in the values of magnetic susceptibility are indicators of the increase in the concentration levels of heavy elements for soils of the basin as a consequence of human contamination. [ABSTRACT FROM AUTHOR]

Measurements of magnetic susceptibility x as a function of temperature in the range 2-300 K on polycrystalline samples of Cu2Cd1-zMnzSnSe4 magnetic semiconductor alloy system are reported. The Curie constant C increase linearly with z. The Curie-Weiss temperature θ and Néel temperature TN increase linearly with z due to a partial order change to total disorder of the Mn+2 ions in the system. In a first approximation, it can be considered that this system has typical spin glass behavior (spin glass system), which means that ions Mn+2 are somewhat disorderly way cationic network of material. [ABSTRACT FROM AUTHOR]

Copyright of La Revista Latinoamericana de Metalurgia y Materiales, RLMM is the property of Universidad Simon Bolivar, Departmento de Ciencia de los Materiales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

En Argentina la explotación de salmueras con contenido económico de litio genera hidróxido de magnesio como residuo de las operaciones de purificación por precipitación química. Este trabajo aborda la recuperación del magnesio de muestras de salmueras, concentradas mediante evaporación, provenientes del salar de Pozuelos (Salta). Los ensayos de precipitación se realizaron a temperatura ambiente (20 ºC) y usando como agente precipitante el óxido de calcio en cantidades estequiométricas y con distintos excesos a 2 000 mL. El avance de reacción se determinó en un reactor tipo tanque agitado discontinuo de 2,5 L de capacidad; la velocidad de agitación fue constante e igual a 200 rpm. Se tomaron muestras de 100 mL luego de transcurridos 5, 15, 30 y 60 min; inmediatamente se separaron los sólidos mediante filtración al vacío y se determinó el contenido de magnesio en los líquidos por espectrofotometría de absorción atómica. Se encontró que el grado de avance de la reacción es independiente de la concentración inicial de magnesio, pero dependiente del valor de pH alcanzado luego del agregado del agente precipitante. Después de la purificación, las salmueras con alto contenido de magnesio (> 5 000 ppm) generan pulpas con bajos grados de filtrabilidad, característica que no varía ni aún con el agregado de floculantes para facilitar la operación de filtración. [ABSTRACT FROM AUTHOR]

This article exposes the resolving power of the magnetic susceptibility measurements in basement minerals samples of the lateritic weathering profile as an element of complementary analysis in the petrographic characterization of the rocks, and useful in the mapping of the magnetic heterogeneities of the basement. The comparison of the magnetic susceptibility data with the petrographic data of different samples revealed that even in samples that correspond to homogeneous lithotypes, great heterogeneities and differences can be manifested from the physicalmineralogical point of view. In general, a high concordance was observed between the intensity of the weathering processes in the rock samples, and the values of the magnetic susceptibility of such samples. The results support the possibility of extrapolating the composition information to samples with magnetic susceptibility measurements and without petrographic studies. [ABSTRACT FROM AUTHOR]

The semidesert region of Zacatecas has been a major driver of economic development sustained at an industrial level by the quantity, quality and price of the minerals found in 13 stunning lithological formations in this state. The study area of approximately 3,744 km2 is characterized by rocks of basaltic composition, rhyolite, intrusive rocks such as granodiorite, monzonite of the terciary period at the beginning of the Cenozoic Era, and also low to medium grade metamorphic rocks also characterized by the type of contact metamorphism of low average degree. Multivariate analysis was used to build hierarchical diagrams (dendrograms) and maps of similarities. The main spots of high magnetic susceptibility were obtained to be in formations from the quaternary, terciary, early Creataceous and late Jurassic periods, which implies that the highest content of ferromagnetic minerals is to be found in this layers of rock and in certain deep mineral structures. [ABSTRACT FROM AUTHOR]

Tailings are a significant source of arsenic and heavy metals. When mining wastes are subjected to wind dispersal and water erosion, they may be the cause of widespread soil contamination. In this work, a mining area in the state of San Luis Potosi, Mexico, was selected to evaluate the use of magnetic susceptibility (MS), electrical conductivity (EC) and pH as alternative indicators for the delimitation of the spatial distribution of arsenic and heavy metals in mine wastes and soils contaminated by their dispersal. The MS, EC, pH and the total concentration of potentially toxic elements (PTE), such as arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), zinc (Zn) and iron (Fe), were determined in 107 waste and soil samples. Moreover, the concentration of major ions in solution was analyzed and XRD and SEM analyses were carried out. Finally the hazard index (HI) was assessed as a value showing the effect of joint presence of As, Cd and Pb in the area. The results indicate that higher values of MS, EC and total concentrations of PTE and the lowest pH values were determined in mining waste, confirming that they are a potential source of soil contamination of adjacent areas. Moreover, soils closest to residues yielded high values for these parameters. There was a strong linear correlation between the MS, pH and the total concentration of PTE and a lower correlation for the EC, which is determined by the presence of calcium sulfate (gypsum) as the main secondary mineral of oxidation processes in mining wastes. Also, the relationship between MS and PTE was determined by solid phases that were contained in the PTE (Fe minerals) with good magnetic response. The linear regression analysis for the hazard index (HI), MS, EC and pH indicates a significant linear correlation between HI and MS (0.82), and between HI and pH (- 0.81). However, only a weak linear correlation between HI and EC was found (r = 0.57). These results suggest that the EC will help to determine the source of contamination and the dispersion of the waste and the MS and pH help in the delineation of soil contamination as well as the assessment of the degree of contamination by mining waste in the study area. [ABSTRACT FROM AUTHOR]

This paper reports the synthesis, structural and magnetic characterization of the alloy CuAl0.67Cr0.33S2. The sample was synthesized using the technique of direct fusion of the constituent elements. Chemical analysis (EDX) allowed establishing the stoichiometric ratios for this alloy. The powder diffraction pattern was indexed and the main phase crystallizes with tetragonal symmetry and unit cell parameters a = 5.3410(1) Å, c = 10.4154(2) Å. This material is isomorphic with the chalcopyrite structure which crystallizes in space group I d 42 . Measurements of magnetic susceptibility and electronic paramagnetic resonance, depending on temperature, were performed in a SQUID magnetometer and a Bruker EMX X- band, respectively. The alloy exhibits a ferrimagnetic ordering with Néel temperature ~ 40 K. The EPR linewidth shows a paramagnetic behavior between 100 and 600 K, while the resonance field and the g factor show a slight variation with temperature. [ABSTRACT FROM AUTHOR]

Copyright of La Revista Latinoamericana de Metalurgia y Materiales, RLMM is the property of Universidad Simon Bolivar, Departmento de Ciencia de los Materiales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The magnetic properties of ferrimagnetic Ising system with mixed spins S = ±3/2, ±1/2 y σ = ±5/2, ±3/2, ±1/2 are studied. The spins are alternated on a square lattice, such that nearest-neighbor interactions occur between different spins (S↔σ), and interactions next nearest-neighbor between spins of the same type (σk↔σl). When the Hamiltonian includes couplings antiferromagnetic between spins S and σ, ferromagnetic and antiferromagnetic between spins σ and D crystal field, it was found that the critical temperature strongly depends on the values of the parameters of the Hamiltonian. The behavior at finite temperature of the total magnetization of the lattice, the magnetization of the sublattices and the total magnetic susceptibility are also studied, taking into account the effects of exchange coupling between next nearest-neighbor and the crystal field of the lattice. For the Hamiltonian studied, there are not compensation points. [ABSTRACT FROM AUTHOR]

Theoretical and practical studies were conducted on the separation of chemical and mineralogical compounds contained in the laterite ore bodies. The degree of theoretical separation that can be achieved is established based on the differences between the physical properties of diameter and the magnetic sensitivity of the mineral particles by using the beneficiation, gravitational and magnetic methods. These results were corroborated through bench trials; which proved the hypothesis that there is no significant difference between the theoretical results (expected frequency) and the bench test results obtained (observed frequency); for which the distribution function χ⊃ (Ji squared) with correction of Yates was used. [ABSTRACT FROM AUTHOR]

Copyright of Revista de la Sociedad Química del Perú is the property of Sociedad Quimica del Peru and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The behavior of the magnetic susceptibility is analized in the rocks that are located in the ophiolitic suite of northeastern Cuba with the aim of know the geological nature of magnetic anomalies. First they are considered the results of petrophysical investigations previous in this region that include the k, next the measurements of k are analyzed carried out in two sampling stages, in those that were collected 374 samples. Starting from the analysis of this property it is known that the same evidences the composition and geologic history of the different type of rocks in the region. Variations are inferred in the grade of serpentinization of the ultramafic rocks, as well as of the enrichment in magnetic minerals in all the studied rocks. The serpentinized peridotites and the gabbros dikes present the highest values in k, indicating in the first case, their serpentinization grade, related of direct way. Both groups of rocks are the main responsible for the magnetic field behavior, the which it should be linked with the geometric and physical characteristics of the ophiolites and some gabbros dikes, associating the high values of the field with the biggest thickness of this rocks. [ABSTRACT FROM AUTHOR]

The optical conductivity data analysis in cuprate optimal doped superconductors from the inversion technique of Marsiglio provides evidence of the carrier-charge coupling to the spin resonance. By means of the theoretical interpretation of the resonance in the spins magnetic susceptibility and the optical conductivity data in Bi2Sr2CaCu2O8+δ (Bi2212) to T = 10K, 100K, 200K, and 295K, one empiric interpretation to the disappearance of the resonance without the necessary disappearance of the carrier-charge coupling is presented like it was recently demonstrated by Timusk et al. [ABSTRACT FROM AUTHOR]

Structural and magnetic properties of Fe0.2Mn0.4Al0.4 alloy, obtained by furnace arc were studied by SEM, DRX, Mossbauer spectroscopy and ac magnetic susceptibility. It was observedt hat this alloy presents a bcc strcuture, with a mean grain size of ≈ 139 ± 3 Å and a typical lattice parameter to this phase. With Mössbauer spectroscopy and ac magnetic susceptibility transition temperature was ≈ 211K which can be associated to an antiferromagnetic (AF) to a paramagnetic (P) phase. That order behaviour was verified by 0.04 T (Tesla) at 77K, and 0.3 T at 292K of external field Mössbauer spectroscopy measurements and the frecuency dependence and dc field of ac magnetic susceptibility. [ABSTRACT FROM AUTHOR]

The specific heat and magnetic susceptibility of periodically modulated XXZ spin-½ chains are studied using the DMRG method. These chains present a non-trivial plateau whose value is given by the relative sizes of the subchains that compose the system being in agreement with the fractional quantization condition. The plateau disappears exponentially as the temperature increases. A transition in the magnetic susceptibility between a trivial and non-trivial plateau was observed. The heat capacity is very small at the lowest temperature showing a wiggled behavior. [ABSTRACT FROM AUTHOR]

By using the Gibbs free-energy variational method based on the Bogoliubov inequality, we study the magnetic properties of the disordered Fe0.9-qMn0.1Alq (0.1 < q < 0.4). These systems, having a random distribution of the constituent atoms, are characterized by exhibiting, besides other variety of magnetic phases, the so-called spin glass behavior as a consequence of the competition between exchange integrals and the dilutor effect of the aluminum atoms. In this work we calculate properties such as the magnetization per site, the magnetic susceptibility and the specific heat as a function of temperature in the Ising model for different stoichiometries. The model is tested for pure iron as a limit case and results are compared with previous reports by using Monte Carlo simulation. Results show a strong dependence of the degree of magnetic frustration on the aluminum concentration, characterized by a magnetization decrease in the low temperature domain. [ABSTRACT FROM AUTHOR]

In this work we carried out the study of the temperature dependence of the magnetization, magnetic susceptibility and heat capacity, in the manganite compound La2/3Ca1/3MnO3. To do that, we employed the Monte Carlo simulation method implemented whit a Metropolis dynamics, and Ising Hamiltonian in three dimensions, magnetic nearest neighbors interactions and periodic boundary conditions in order to stress on the bulk properties. In the model, the charge orbital ordering of Mn3+ and Mn4+ ions has been considered according to literature. Likewise, we have taken into account the different manganese spin values, S(Mn+3)=2, S(Mn+4)=3/2. As input parameters, we have used those of the exchange integrals Jab, Jab1 and Jab2, which respectively correspond to Mn3+- Mn3+ (eg- eg'), Mn3+- Mn4+ (eg-d³) and Mn3+- Mn4+ (eg'-d³) bonds. Results show the contributions to the magnetization and to the susceptibility for the different sublattices depending on the manganese ion and the orbital type. Results also provide detailed information about the ferromagnetic arranging below the Curie temperature. Finally, the outputs are compared with experimental data reports. [ABSTRACT FROM AUTHOR]

We calculate analytic and numerically the electric susceptibility of a three-level atoms system coupled to a quantized single mode field and to a classical control field, such that the whole system shows electromagnetically induced transparency (EIT). The calculations of the complex susceptibility allow us to determine the refractive index and the transmission of the signal (quantized single mode field) as a function of detuning. [ABSTRACT FROM AUTHOR]

The AC losses are the dissipated energy in the material per unit volume and per cycle of the applied magnetic field. They are associated to the imaginary part of the AC susceptibility. A setup was made for measuring the AC susceptibility in superconducting samples based on the compensed coils and Lock-in Amplifier method. This system allows as to measure the AC losses as function of temperature, amplitude and frecuency of the magnetic field for temperatures from ambient down to 65K. In this paper we give a detailed description of the implemented measuring system [ABSTRACT FROM AUTHOR]

Perovskite materials possess a varied spectrum of properties and applications. This has ideal crystalline structure given by the formula ABO3. The perovskites with stoichiometric formulas A2BB'O6 or A3B2B'O9 are denominated complex perovskites. These materials have extensively studied because the flexibility in the variation of the lattice parameters permits to infer their possible application as substrates for the production of high temperature superconducting films. In this work we report the synthesis and characterization of the complex perovskite: Ba2TRMO6, where TR: Ho, Dy, and M=Nb, Hf, Sb, Zr. We study crystallographic, microestrutura and magnetic properties of this system by means EDX, DRX, SEM and magnetic susceptibility techniques, respectively. [ABSTRACT FROM AUTHOR]

Field frequency dependence with the ac magnetic susceptibility in S/AF/F trilayers was studied. Trilayers were deposited in situ onto (001) SrTiO3 substrates using the dc sputtering technique. ac susceptibility measurements, Χ'+ Χ'', were performed under an alternative field amplitude of hac=0.1 Oe applied along to (001)-direction, and frequencies from 1.1 kHz and 51.1 kHz. Trilayers displayed a diamagnetic behavior below TC~ 76 K, susceptibility data shown that superconducting transition wide ΔTC and the superconducting volume fraction fg with the frequency increasing are no affected. Applying the Jönnson model to ... effective pinning energy was obtained in the flux creep and flux flow regimens. [ABSTRACT FROM AUTHOR]

We report the study of thermal fluctuations on the magnetic susceptibility for the CLBCO superconducting system, in the limit of low magnetic fields, above the critical temperature (Tc0=77 K). We used the concept of magnetization excess and performed the analysis by means the LD model, which permits to calculate the diamagnetism induced from the thermal fluctuations in the normal state, close to Tc0. [ABSTRACT FROM AUTHOR]

The design and construction of the first vibrating sample magnetometer developed in the country, is herein presented. A vibrating sample magnetometer measures the magnetic moment of a sample when such vibrates in the presence of a magnetic static field, from which it is possible to determine the magnetization and the magnetic susceptibility. Said low-cost magnetometer is remarkable given its versatility and simplicity; allowing us to obtain precise and reliable results. Its operation is based on the Lenz law of induction. Currently, the movement of the sample is carried out by using a Mösbauer driver that allows the control of the mechanical vibration of the sample, of its amplitude, and its frequency by feedback to a PID controller. The sensibility of the magnetometer is sufficient to detect a minimal change in the magnetic moment of 5 x 10-4 emu. [ABSTRACT FROM AUTHOR]

The following work shows the magnetic properties correspondence of the various mineral phases which form the intemperism crust of the ultrabasic rocks with the Fe, Ni and Co chemical elements contents. This permits lo enrich chemical-mineralogycal knowledge about on his genesis and serves in addition to base more effective for the development of the industrial process, with the consequent increase in the recover of Ni and Co in a general way in the ammonium carbonate technology. [ABSTRACT FROM AUTHOR]

In this paper the behaviour of the onset temperature of superconducting transition and the volumen fraction of superconducting phase in Y-Ba-Cu-O and Bi-Sr-Ca-Cu-O ceramics under gamma 60Co radiation dose are analyzed by measurement of dynamic magnetic susceptibility at 77 K. Also the effects of gamma radiation on the transport properties of Y-Ba-Cu-O are presented. [ABSTRACT FROM AUTHOR]

Copyright of FABICIB: Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral is the property of Universidad Nacional del Litoral and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Using solid state method reaction we made in Argon atmosphere bulks of the doped system TiO2 with vanadium Ti1-xVxO2 at 1200 °C. The paramagnetics properties of the bulk material were investigated by magnetic susceptibility measures as function of temperature between 90K - 140K. Resistance measurements were developed as function of temperature, between 50K - 300 K, in presence of different longitudinally magnetic fields. Results show a paramagnetics behavior, we observed that the magnetic susceptibility decrease with the increase of the doping vanadium and the temperature in the samples. The resistivities plots show a semiconductor behavior. [ABSTRACT FROM AUTHOR]

In the present work we report the magnetoelectric characterization of the new manganite Sr2TiMnO6 perovskite-like material. From measurements of magnetization as a function of temperature we determine the occurrence of a magnetic ordering for a critical temperature Tc=44.8 K and the existence of an irreversibility point at the magnetization measurements as a function of temperature for the Zero Field Cooling (ZFC) and Field Cooling (FC) regimes, became a strong evidence of frustration. Curves of magnetization as a function of applied field show a hysteretic behavior, characteristic of ferromagnetic materials. Curves of polarization as a function of applied voltage exhibit a ferroelectric response. Results reveal the occurrence of magnetoelectric response for the temperature regime T<44.8 K. [ABSTRACT FROM AUTHOR]

A direct relationship between heavy minerals contens and magnetic susceptibility in an alluvial deposit has been observed in samples taken in a bore hole made at the shore of the Nechi river in NE of the Antioquia Department. These results are explained by the similarity of physical properties of these minerals. Analysis of energy spectrum has verified these relations. [ABSTRACT FROM AUTHOR]