Добірка наукової літератури з теми "Gravure du chrome massif"

Relevance of the work. The conditions for the formation of chromium ores in alpine-type ultramafites remain a topical subject of research. In recent years, scientific papers have focused on the issue of changing the chemical composition of ore-forming minerals and chromium ores under the influence of deformation and dynamic recrystallization processes accompanying metamorphism. The results of such studies make it possible to formulate a new model of the formation of chromium mineralization taking into account a significant amount of geological data indicating that alpine-type ultramafic rocks are “mantle tectonites”. In our work, we have studied zonal ore-forming spinels from chrome ores of the Polar Urals. The results of the study make it possible to associate the formation of chemical zoning in minerals and ore bodies with recrystallization under the influence of stress tension. Purpose of the work – study of the conditions for the formation of chemical zoning of chromium spinels from alumina and medium chromium ores of the Voikaro-Syninsky massif. Results. Zonal ore-forming spinels from medium-chromium and aluminous chromitites of the Voikaro-Syninsky massif (Polar Urals) have been studied. It was found that replacement rims are developed along the grains of oreforming spinels with an increased content of Cr2 O3 and an oxidation state of iron in relation to the core, as well as a reduced content of Al2 O3 . The oxidation state of iron in the rims of most grains does not exceed the values typical for unaltered ore-forming spinels. T–fO2 parameters of zoning formation in spinels were determined by oxythermobarometry. Comparison with zoned chrome spinels of the Golyamo Kamenyane massif (Bulgaria). Conclusion. Metamorphic transformations of alumina and medium-chromium chromitites of the Voikaro-Syninsky massif, occurring under subcrustal conditions under the action of directional stress at relatively constant T–fO2 parameters, lead to an increase in the chromium content of the ore mineral.

The overall objective was to create a geological and geophysical field test site for chromite mineralization and detailed works in order to determine and test the main search criteria for disseminated mineralization. To create a field test site, an area was selected in the southern part of the Klyuchevsky massif characterized by abundant development of disseminated mineralization in the banded dunite-clinopyroxenite complex and strong processes of superimposed metamorphism. This paper gives a piece of research on the composition of chrome spinel from disseminated ores that underwent metamorphism of different stages. The composition of chrome spinelide, the evolution of its metamorphism and the related changes in its magnetic properties are examined in detail. It was established that all chrome spinels are of a high-chromium type, to one degree or another, they were subject to secondary changes, leading to the appearance of magnetic phases. The degree and nature of the change in chrome spinels in dunites directly depends on the degree of metamorphism of the rocks. The formation of the magnetic phase begins with the formation of nuclei consisting of single magnetic dipoles, groups of 2-3 dipoles or chains of magnetic dipoles, which was first discovered by us in chrome spinel grains. Then there is an increase in the number of such phases, the appearance of optically diagnosed secondary changes in chrome spinelide. A comparison of the degree of variation of chrome spinel and its reflection in the pattern of recorded anomalies of geomagnetic fields allows us to identify some criteria for the search for disseminated chromite ores of this type.

Research subject. The metamorphic ultramafites of the Kalninsky and Ergaksky massifs located in the northeastern part of Western Sayan (Russia) constitute the Kurtushibinsky ophiolite belt. These rocks are considered to be potentially interesting as bearing chromium and noble metals, which fact determines the relevance of this research.Materials and methods. Thin and polished sections of silicate and ore minerals from the ultramafic rocks under study were investigated using a polarizing microscope AxioScop, Carl Zeiss. The chemical composition of minerals was determined by the method of X-ray spectrum microanalysis using a scanning electron microscope Tescan Vega II LMU equipped with an energy-dispersive spectrometer INCA Energy 350 and a wave-dispersive spectrometer INCA Wave 700. The petrochemical composition of the rocks was studied by the methods of XRF analysis using an X-ray fluorescence energy-dispersive spectrometer Oxford ED-2000. A quantitative ICP-MS analysis was carried out using an Agilent 7500 spectrometer.Results. The massifs are found to be composed of dunites and harzburgites, which were formed during an uneven depletion of the mantle. As a result of depyroxenization, the ultramafites were enriched with chromospinelides. Subsequent intense plastic deformations contributed to their segregation into ore bodies. Regenerated olivinites predominate in the northern part of the Ergaksky massif. The microstructural features of ultramafites and the composition of minerals indicate them to have been subjected to inhomogeneous high-temperature plastic deformations, which occurred during their migration in the upper mantle and crust.Conclusions. The petrochemical studies have shown that the ultramafites of the Ergaksky massif are least depleted, frequently featuring clinopyroxene. The most depleted ultramafites of the Kalninsky massif are characterized by a more extensive distribution of dunites, the absence of clinopyroxene and lower contents of REE and rare elements in comparison with the ultramafites of the Ergaksky massif. The obtained geochemical data indicate a fluid-magmatic effect of boninite melts on depleted ultramafites, which apparently occurred under mantle conditions over the subduction zone and consequently led to their enrichment with incompatible LREE (La, Ce) and Sr, Zr and Hf, as well as to the formation of high-chromium chromitites.

The results of investigations of natural iron-chromium spinels of variable composition Fe2+(Cr2-xFex3+)O4 of the chromite-bearing Klyuchevskoi massif (Middle Urals), which are the main carriers of the magnetization of rocks are presented. Substantial changes in the composition and in magnetic structure of accessory chrome-spinels scattered in the host rock are established, unlike the almost unaltered ore-forming chrome-spinels, under the influence of secondary geological processes. To establish the connection between the chrome-spinel changes at the microlevel and features of the geomagnetic field anomalies created by this carrier of magnetization of rocks, it is carried out a complex of investigations of Fe-Cr-spinels (thermomagnetic analysis over the temperature range (4÷1000) K; magnetic resonance (MR) spectroscopy and magnetic force microscopy (MFM) in addition to magnetomineralogical studies). As a result, in the relict areas of grains of the accessory chrome-spinels were first discovered the magnetic clusters (superparamagnetic phases) in the form of single or groups of 2 – 3 magnetic dipoles of tens nanometers in size, or in the form of chain-like structures of magnetic dipoles/single domains.

The composition and age of subalkaline dolerites localized in chromite-bearing ultramafic rocks of the Rai-Iz massif are investigated. Dolerites are traced along tectonic zones inside ultramafic rocks and are not observed beyond their boundaries, spatially tending to deposits and occurrences of chromites.The studied dolerites are characterized by high concentrations of alkalis, TiO2, P2O5, enrichment with large-ion lithophilic elements and Th; the amount of REE varies from 103.3 to 164.2 ppm; (La/Sm)n = 1.3–1.7. The age of subalkaline dolerites was determined by the method 40Ar/39Ar (402.7 ± 3.8 million years). At this time, a deep metamorphic processing of ultramafic rocks of most of the Rai-Iz massif occurred with the formation of high-chromium chrome mineralization and the isolation of a vein series of subalkaline dolerites in the discharge zones.

Research subject. Minerals and mineral assemblages of noble elements in chromitites of the Alapaevsk massif. Aim. A systematic mineralogical study of high-chromium (Cr) and alumina-rich (Al) chromitites with the development of a sequence scheme for mineral formation, including platinum-group minerals (PGMs) and gold alloys. Materials and Methods. Samples of high-Cr and Al chromitites from chromite deposits in various parts of the Alapaevsk massif. Scanning electron microscopy (Tescan VEGAII XMU and JSM-6390LV Jeol with EDX INCA Energy 450 X-Max 80 spectrometers) and electron microprobe analysis (Cameca SX 100 with five wave spectrometers) were used. Results. A diagram showing the sequence of mineral formation in chromitites was designed; primary and secondary mineral assemblages were distinguished, with the latter assemblage being divided into early and late mineral associations. Primary assemblages of high-Cr (Cr2O3 > 50 wt %) and Al (Cr2O3 < 50 wt %) ores are represented by similar minerals, including chromespinel, clinopyroxene, and olivine, with characteristically distinct compositions of these minerals in each type of ores. Minerals of the primary assemblage are synchronous with chrome-spinel and are represented by pentlandite, Cu-bearing pentlandite, chalcopyrite, pyrrhotite, bornite, as well as PGMs (laurite RuS2, erlichmanite OsS2, native osmium) and Cu-rich gold. Minerals of the secondary early association occur in the form of polyphase inclusions within chrome-spinel. Polyphase inclusions are composed of Cr-bearing chlorite, amphibole, garnet, sulfides (millerite, heazlewoodite) and minerals of native elements, including (Ni, Cr)-bearing copper, nickel-bearing copper, (Cu, Fe, Cr)-bearing nickel, awaruite. Noble metal minerals from the secondary early association were found only in Al chromitites and are represented by laurite, Pt- and Pd arsenides and stibnides, Ru-bearing pentlandite, and high-grade native gold. The secondary late mineral association consists of native copper and awaruite, which are intergrown with serpentine in high-Cr ore. The temperature conditions for the formation of secondary assemblages were estimated using a chlorite geothermometer. The formation temperatures of the studied chlorites from chromitites fall within the range of 250–284°C. Conclusions. Noble metal minerals from secondary associations were formed at temperatures below 350°C together with garnet, amphibole, chlorite, and nickel sulfides. Grains of primary Os–Ir–Ru alloys during epigenetic processes underwent sulfurization with the formation of a fine-grained porous mixture of native and sulfide (sometimes with As) phases, and replacement by Ru-pentlandite. The presence of awaruite and native Cu and Ni in both primary and secondary assemblages of chromotites indicates the reducing conditions for the formation of noble metal minerals. The limited occurrence of high-Cr ores, along with the manifested processes of sulfurization for primary grains of Os–Ir–Ru alloys, led to the scarcity of detrital PGM in the area of the Alapaevsk massif.

Research subject. Chromite ores and massive chromitites with alumina (low chromium) chrome spinelide (the Podennoye deposit deposit) and chromite ores with high-chromium chrome spinelide (Kurmanovskoye deposit) of the Alapaevsky hyperbasite massif. Materials and methods. Samples of chromite ores and massive chromitites collected during field research were studied in transparent sections using chemical analysis and electrical methods (electrical conductivity, dielectric losses). Results. The temperature dependences of electrical resistance and dielectric losses in the temperature range of 20‒800°C were obtained. The electrical parameters lgRₒ and Eₒ were determined, and the inverse linear relationship bet-ween them was revealed. The electrical parameters for the three groups of samples were found to differ depending on the degree of metamorphic changes. It was established that an increase in metamorphism leads to an increase in lgRₒ and a decrease in Eₒ. For the studied samples of chromite ore from the Podennoye deposit, Eₒ and lgRₒ vary from 0.61 to 0.96 and from 2.5 to –0.41, respectively. In the Kurmanovskoye field, these parameters vary from 0.81 to 1.35 and from 0.95 to –2.8, respectively. For the studied samples of chromitites from the Podennoye deposit, Eₒ varies from 0.21 to 0.41, while lgRₒ varies from –0.08 to 1.67. In this case, the coefficients a and b are different for each group of samples. For some samples, the chemical composition was determined, and for six samples (two samples from each group), the content of ferrous and trivalent iron oxides in the original sample and a duplicate sample after calcination at temperature of up to 800 °C was determined. Relative change in the ratio of ferrous and trivalent iron oxides in the initial sample (FeO/Fe2O3)* and a duplicate sample (FeO/Fe2O3)** H = [(FeO/Fe2O3)*/(FeO/Fe2O3)**] was compared with the position of the maximum of dielectric losses on the temperature scale. In the coordinates H–T, °C, the studied samples, depending on the metamorphic changes, occupy a certain place. Conclusions. The study indicates the potential of the obtained information to be used as petrogenetic indicators of chromite deposits with a simultaneous assessment of the degree of metamorphic changes.

La structuration à l’échelle submicronique de la surface des aciers inoxydables permet de leur apporter de nouvelles fonctionnalités, par exemple pour des applications tribologiques et optiques. Cette thèse s’inscrit dans le cadre du projet ANR SPOT qui a pour objectif de structurer à l’échelle submicronique la surface d’aciers austénitiques et martensitiques par gravure sèche. Dans ce travail, nous avons développé un procédé plasma avec un mélange de chlore et d’argon pour la gravure des aciers inoxydables. La mise au point de ce procédé a été réalisée en se basant sur l’étude de la gravure des métaux principaux qui composent ces aciers, à savoir, le fer, le chrome et le nickel. En se basant sur des mesures de vitesses de gravure, ainsi que sur des techniques de diagnostics plasmas, nous avons montré que, dans un plasma de chlore et d’argon, le fer est l’élément qui se grave le plus, suivi du chrome puis du nickel. Les échantillons métalliques ainsi que les aciers inoxydables gravés ont été analysés par des techniques de caractérisation de surface notamment des analyses de spectrométrie photoélectronique X (XPS). Nous avons également étudié la variation des vitesses de gravures de ces métaux et de ces aciers en fonction de la température des substrats. Ces études nous ont permis d’établir les mécanismes mis en jeu en cours de la gravure des éléments métalliques. Nous avons montré que, dans un plasma de chlore et d’argon, le fer se grave principalement par un mécanisme chimique qui suit une loi d’Arrhenius. Ce mécanisme serait basé sur la formation de chlorures de fer volatiles. Dans le cas du chrome, la gravure nécessite une assistance ionique afin de désorber les chlorures de chrome non volatiles formés à la surface du matériau. Enfin, pour le nickel, nous avons observé que la vitesse de gravure diminue lorsque la température augmente. Dans ce cas, des observations au microscope électronique à balayage ont permis de mettre en évidence la formation de gonflements riches en chlore. Les analyses XPS de la surface gravée du nickel suggère que ces gonflements sont dus à la formation de chlorures de nickel non volatiles. Ces chlorures seraient à l’origine de la diminution de la vitesse de gravure du nickel dont la pulvérisation se trouverait bloquée par la présence de ces chlorures. La compréhension de ces mécanismes a permis de conclure que, dans un plasma chloré, l’élément bloquant dans la gravure des aciers inoxydables est le nickel
The structuring at sub-micronic scale of the surface of stainless steels allows to provide them with new functionalities, for example for tribological and optical applications. This thesis is part of the ANR SPOT project which aims to structure the surface of austenitic and martensitic steels on a submicronic scale by dry etching. In this work, we have developed a plasma process with a mixture of chlorine and argon for the etching of stainless steels. The development of this process was carried out based on the study of the etching of the main metals that make up these steels, namely, iron, chromium and nickel. Based on measurements of etching speeds, as well as on plasma diagnostic techniques, we have shown that, in a chlorine and argon plasma, iron is the most etched element, followed by chromium, then nickel. The metallic and the stainless steels etched samples were analyzed by surface characterization techniques, in particular X photoelectron spectrometry (XPS) analyzes. We have also studied the variation of the etching speeds of these metals and steels as a function of the temperature of the substrates. These studies have enabled us to establish the mechanisms involved in the etching of metallic elements. We have shown that in a plasma of chlorine and argon, iron is mainly etched by a chemical mechanism which follows an Arrhenius law. This mechanism would be based on the formation of volatile iron chlorides. In the case of chromium, the etching requires ionic assistance in order to desorb the non-volatile chromium chlorides formed on the surface of the material. Finally, for nickel, we observed that the etching speed decreases when the temperature increases. In this case, observations with a scanning electron microscope made it possible to highlight the formation of swellings rich in chlorine. XPS analyzes of the etched surface of nickel suggest that these swellings are due to the formation of non-volatile nickel chlorides. These chlorides would be at the origin of the decrease in the rate of etching of nickel, the sputtering of which would be blocked by the presence of these chlorides. Understanding these mechanisms led to conclude that, in a chlorinated plasma, the blocking element in the etching of stainless steels is nickel

En Nouvelle-Calédonie, 35 Ma d'intense altération et d'érosion de roches ultrabasiques ont permis le développement d'une couverture latéritique riche en éléments traces métalliques (Ni, Cr, Co, Mn). Dans ces sols, ces éléments traces métalliques (ETM) constituent un risque pour l'environnement endémique de la Nouvelle-Calédonie. Parmi ces ETM, le Cr est le plus abondant (jusqu'à 3,8% en poids de Cr₂O₃) mais également le plus toxique, suivant son degré d'oxydation. Après avoir étudié la redistribution des éléments majeurs et traces au cours du développement d'un régolithe de 64 mètres d'épaisseur dans le massif du Koniambo (Côte Ouest, Province Nord de la Grande-Terre), une étude détaillée de la cristallochimie du chrome a permis de mieux comprendre le comportement de cet élément le long de cette séquence d'altération. Principalement sous forme Cr(III), le Cr est partiellement oxydé en Cr(VI) par le biais d'oxyhdyroxydes de Mn (III/IV), s'accumulant à l'interface saprolite-latérite dans la séquence d'altération péridotitique. Ces oxyhydroxydes de Mn sont également soupçonnés d'augmenter la solubilité des chromites, minéraux réputés peu solubles. Compte tenu de la grande solubilité du Cr(VI), l'oxydation du Cr(III) devrait augmenter significativement le lessivage du chrome le long de la séquence. Cependant, les bilans de masse par la méthode Brimhall indiquent une mobilité très limitée pour le chrome, même si cette dernière semble un peu plus élevée dans les niveaux riches en oxyhydroxydes de Mn. En effet, des analyses résolues spatialement indiquent qu'une fois oxydé, le Cr(VI) est réadsorbé par les oxyhdyroxydes de Fe, abondants dans ces environnements latéritiques, soulignant l'importance des oxyhydroxydes de Fe pour limiter cette remobilisation
In New-Caledonia, 35 Ma of deep weathering of ultramafic rocks yield soils strongly enriched in metallic trace elements (Ni, Co, Cr, Mn). In these soils, these large amounts of metallic trace elements constitute a significant risk for the environmental quality of this peculiar environment. Among these metallic trace elements, chromium is the most problematic because it is the most abundant (up to 3,8 wt% of Cr₂O₃), but also that showing the largest toxicity potential, depending on its redox state. After studying the redistribution of major and trace elements upon the formation of a 64 meters depth regolith in the Koniambo outcrop, a detailed study of the crystal-chemistry of chromium allowed to better understand thé behavior of this element along the weathering sequence. Initially as Cr(III), Cr is partially oxidized to Cr(VI) after redox reactions with Mn-oxyhydroxydes which accumulate at the boundary between the saprolitic and lateritic levels of the sequence. These Mn-oxyhydroxydes are also suspected to significantly increase the solubility of chromite, a mineral species usually considered as almost insoluble Regarding the very large solubility of Cr(VI), such an oxidation of Cr(III) should significantly increase the leaching of chromium along the sequence. However, mass balance with the Brimhall method indicate a quite restricted mobility for chromium, although slightly larger in the Mn-enriched levels. These observations are explained by the results of spatially-resolved analyses which show that, once oxidized by the Mn-oxyhydroxydes, Cr(VI) is re-adsorbed by the Fe-oxyhydroxydes (mainly goethite), abundant in these lateritic environments, underlying the importance of Fe-oxyhydroxydes to mitigate this leaching

Dans le site étudié du Massif de Szklary (Pologne), Ni et Cr sont présents à des concentrations élevées dans deux environnements d’origine distincte : naturelle (sols développés sur serpentinites) et industrielle (haldes de déchets pyrométallurgiques issus de l’exploitation du Ni). L’objectif de cette étude est de localiser les minéraux porteurs d’éléments potentiellement toxiques (EPT), principalement de Ni et Cr, dans ces divers environnements et de comparer leur mobilité dans les conditions actuelles d’altération (climat tempéré transitionnel de Pologne). Ces travaux s’intéressent également à l’évaluation du risque environnemental causé par l’abondance du Cr, du Ni, et par la présence d’autres EPT (Co, Cu, Pb et Zn) à Szklary. Ces éléments se retrouvent notamment dans les sols cultivés dans l’environnement immédiat des haldes de déchets. L’identification des formes solides porteuses de Ni et Cr a été réalisée par approche minéralogique (DRX, MEB-EDS, EPMA, micro Raman, MET) et par analyses chimiques (ICP-MS, extractions sélectives et séquentielles). Ces deux approches complémentaires ont donné des résultats concordants. Alors que les observations minéralogiques fournissent une indication qualitative de la stabilité effective des métaux dans les conditions superficielles actuelles (sols drainants, oxydés, riches en matière organique, de pH neutre à légèrement basique), les analyses chimiques précisent la spéciation solide des métaux en termes quantitatifs et mettent en évidence l’implication des phases organiques et amorphes dans l’immobilisation actuelles des EPT. De plus, l’analyse minéralogique des résidus d’extractions séquentielles a permis de contrôler l'effet des solvants chimiques sur les différents matériaux étudiés. L’ensemble des analyses minéralogiques et chimiques revèlent la stabilité relative du Cr par rapport au Ni dans le site étudié. Ils confirment en outre la contamination du sol cultivé près des haldes par les déchets industriels. Bien qu’apportés en moindre quantité par l’activité industrielle, Zn et Cu présentent un risque environnemental, car ils se retrouvent actuellement immobilisés dans des fractions plus biodisponibles que les fractions contenant Ni et Cr
The geological unit called Szklary Massif comprises two environments containing Ni and Cr from diverse origins: lithogenic (serpentine soils) and anthropogenic (pyrometallurgical waste) origins. The study was dedicated to investigate the distribution and mobility of Ni and Cr occurring within this small area. The approach is first based on mineralogical characterization of the Ni and Cr bearing minerals using analytical instrumental methods (XRD, SEM-EDS, EPMA, micro Raman, TEM, ICP-MS). Later complementary chemical extractions not only provide information about the actual solid speciation of Cr, Ni. They also allow discussing about potential mobility and forthcoming environmental impact induced by the abundance of Ni and Cr and by the presence of other elements (Co, Cu, Pb and Zn), especially in soils cultivated in the dump vicinity. The multidisciplinary approach gives concordant and complementary results. The direct mineralogical approach, consisting in characterization of primary and secondary mineral phases, provides qualitative information about the stability of potentially toxic elements (PTE) in minerals in the present weathering conditions (well drained soils, enriched in organic matter, within neutral to basic pH, submitted to transitional temperate climatic conditions). The chemical extractions specify the solid speciation of PTE in a quantitative way and evidence implication of organic and amorphous phases in the PTE immobilization. In addition, mineralogical investigations of the solid residues after sequential extractions allow assessment of the real effect of the chemical extractants used on the studied materials. The use of combined approach evidenced relative stability of Cr compared to Ni. Moreover, the study confirms contamination of the cultivated soils located next to the waste dump. The environmental risk is related not only with Ni and Cr but also with other PTE such as Zn and Cu, which are present in significant proportions within biodisponible fractions

Le but de cette thèse est l'étude structurale des alliages Fe-Cr sous forme massive – transformation de phase ? (cubique centré) ? ? (tétragonal) – et en couche mince, en utilisant principalement la spectrométrie Mössbauer, et en complément, la diffraction des rayons X. Une caractérisation structurale précise de la transformation de phase à 700 °C dans des alliages massifs FeCr à gros grains a été menée. Le résultat le plus pertinent, mis en évidence par l'effet Mössbauer, est l'existence d'une phase intermédiaire appelée ' entre la phase  initiale et la phase  finale. La diffraction des rayons X a permis de rejeter l'hypothèse d'une structure de type B2 pour cette phase ' de structure équivalente à . La microdiffraction Laue a permis de montrer qu'il n'existait pas de relations simples d'orientations cristallographiques entre les deux phases. Notons aussi que le module d'Young de la phase  a été mesuré pour la première fois ; sa valeur est légèrement supérieure (10%) à celle de la phase . Des films minces Fe1-xCrx de 220 nm d'épaisseur ont été élaborés par pulvérisation ionique directe. Pour 0 < x ≤ 0,28, les films présentent un comportement ferromagnétique, alors que des spectres CEM paramagnétique sont obtenus pour 0,32 ≤ x< 0,70. La transition ferromagnétique à paramagnétique (F/P) à température ordinaire apparaît dès xc ~ 0,30 ; cette valeur critique dépend du mode de préparation. Enfin, un parallèle très intéressant peut être fait au niveau de la transformation de phase pour la concentration equi atomique entre l'alliage à l'état massif et sous forme de couche mince. En effet, les états magnétiques de début et de fin de transformation sont opposés. On part de la structure cc () ferromagnétique dans le massif pour aller vers la structure tétragonale () paramagnétique ; alors que dans les couches minces, c'est une structure A15 (), paramagnétique qui se transforme en structure cc () ferromagnétique
The goal of this thesis is the structural study of bulk – phase transformation  (body-centered cubic)   (tetragonal) at 700 °C – and thin films Fe-Cr alloys by Mössbauer spectrometry and X ray diffraction. An accurate structural characterization of the phase transformation at 700 °C in bulk FeCr alloys with coarse grains was carried out. The most relevant result, highlighted by the Mössbauer effect, is the existence of intermediate phase so-called ' between initial phase  and final phase . The X-ray diffraction made it possible to reject the assumption of a B2 structure for the ' phase which structure is similar to the  one. Laue's microdiffraction has shown that there were no simple crystallographic orientation relationships between the two phases. Let us note that we measured for the first time, the Young's modulus of the  phase; its value is slightly higher (10%) than the  phase one. Fe1-xCrx thin films with 200 nm thicknesses were prepared by ion beam sputtering. For 0 < x ≤ 0. 28, the films present a ferromagnetic behavior, whereas paramagnetic spectra CEM are obtained for 0. 32 ≤ x< 0. 70. The ferromagnetic to paramagnetic transition (F/P) at room temperature appears at xc ~ 0. 30; this critical value depends on the preparation method. Finally, a very interesting parallel can be made concerning phase transformation for the equiatomic concentration between bulk and thin film alloys. Indeed, the starting and final magnetic states of the transformation are opposites. In the bulk alloys, the phase transformation starts from ferromagnetic bcc structure () and goes toward the paramagnetic tetragonal structure (), whereas in the films, a paramagnetic A15 structure () transforms in ferromagnetic bcc structure ()

The Aganozero chromium ore deposit, located in the Pudozh District, Karelia, is a complex object for ore and non-metalliferous useful minerals such as chromium ores, platinoids, chrome spinellids as well as Mg-bearing and high-Mg raw materials, e.g. serpentinite, olivinite, dunite and building materials. The primary goal of the present paper is to assess the radiation-hygienic situation at the Burakovian-Shalozero-Aganozero massif, which comprises the Aganozero deposit. Our assessment is essential in connection with the Megaproject to be launched in Karelia, where the Aganozero deposit will play the key role. Our assessment is based on the field and laboratory studies conducted by the authors with regard for the data obtained for this deposit by the Karelian Geological Survey and the appraisal of the radiation-hygienic situation in the Pudozh District done earlier by Nevskgeologia GTP, VSEGEI.