Terms Of Magnetic Susceptibility Research Articles

Magnetite in Muong Nong‐Type Australasian Tektites From South China

AbstractSouth China belongs to the northern geographic branch of the Australasian strewn field (AASF) of tektites and microtektites, and this area is assumed to be part of the uprange region of the putative impactor trajectory that formed the yet undiscovered source crater. Ferromagnetic minerals in impact glass may record the magnetization process and thermal history of impact melt, but the possible identity of ferromagnetic minerals in AASF tektites from South China is elusive. Here, we perform a rock magnetism and crystallography study of iron‐sulfur spherules in Muong Nong‐type tektites from South China, revealing abundant single‐domain and pseudo single‐domain nano‐grains of magnetite within the spherules. This result is consistent with the detection of magnetic signals caused by single‐domain and pseudo single‐domain magnetite in these samples. Compared to the large value ranges of magnetic properties of tektites in the entire strewn field, individual specimens of both Muong Nong‐type and single splash‐form tektites have relatively homogeneous magnetic properties in terms of magnetic susceptibility, natural remanent magnetization (NRM), saturation isothermal remanent magnetization (SIRM) and NRM/SIRM ratio. The results indicate that the impact melt that formed each tektite specimen experienced similar thermal history, and most AASF tektites from South China were cooled in an ambient magnetic field that is the same order of magnitude as the Earth's magnetic field.

Bipartite entanglement via distance between the states in a one dimensional spin 1/2 dimer copper acetate monohydrate

In this paper, we used a theoretical measure known as distance between the states, , to determine the bipartite entanglement of a one dimensional magnetic dimer system. The calculation was compared with the well-known entanglement measure, concurrence, and found to be the same. was, then, expressed in terms of two thermodynamic quantities, namely, magnetic susceptibility and specific heat. Experimental verification of temperature variation of the bipartite entanglement measure in terms of magnetic susceptibility and specific heat was done on single crystals of copper acetate-an excellent one dimensional dimer system. The results showed the existence of bipartite entanglement till temperatures as high as room temperature! Large sized single crystals of copper acetate were grown by a new evaporation technique and characterised by thermogravimetric analysis, IR and Raman spectroscopy measurements. Density functional theory calculations were done to calculate the delocalisation index which showed much lower values of than other bonds, implying that the probability of direct Cu–Cu exchange in copper acetate is very small. Band structure calculations revealed the presence of flat bands at the Fermi level implying very weak intermolecular interactions in copper acetate.

Innovative technology for preparation of high-purity silica from vein quartz ore through S-HGMS coupling acid leaching process

In the present work, an S-HGMS coupling acid leaching technology was established to prepare high-purity silica using vein quartz ore. Firstly, the magnetic properties of different phases in vein quartz were investigated through density functional theory (DFT) calculations and arranged the phases in terms of magnetic susceptibility: FeP2 > Al2SiO5 > SiO2 > Ca(Al2Si2)O8 > AlPO4. Those differences in magnetic susceptibility resulted from the spin state of electrons in the ions. After treatment using the S-HGMS process, weakly magnetic particles are effectively separated from silica particles, and the obtained silica concentrate contained SiO2 of 99.690% purity. Subsequently, lattice impurity ions were removed through a fluorine-free and low-fluoric acid leaching process. Under optimal conditions, the SiO2 purity in high-purity silica reached 99.954% and 99.990% in the two processes. The lattice parameters and volume of ɑ-quartz in high-purity silica obtained with low-fluoric acid leaching were less than those obtained with fluorine-free acid leaching. This difference can be attributed to the reaction between HF molecules and lattice impurity ions, resulting in the generation of coordination compounds. Meanwhile, HF dissolved SiO2 and opened the lattice impurity ions channel, promoting lattice impurity ions depth removal. This study established a complete set of critical technologies for preparing high-purity silica from vein quartz through the S-HGMS coupling acid leaching process, providing theoretical and scientific bases for industrial applications.

R-Process with Magnetized Nuclei at Dynamo-Explosive Supernovae and Neutron Star Mergers

Nucleosynthesis at latge magnetic induction levels relevant to core-collapse supernovae and neutron star mergers is considered. For respective magnetic fields of a strength up to ten teratesla, atomic nuclei exhibit a linear magnetic response due to the Zeeman effect. Such nuclear reactivity can be described in terms of magnetic susceptibility. Susceptibility maxima correspond to half-filled shells. The neutron component rises linearly with increasing shell angular momentum, while the contribution of protons grows quadratically due to considerable income from orbital magnetization. For a case j = l + 1/2, the proton contribution makes tens of nuclear magnetons and significantly exceeds the neutron values which give several units. In a case j = l − 1/2, the proton component is almost zero up to the g shell. A noticeable increase in the generation of corresponding explosive nucleosynthetic products with antimagic numbers is predicted for nuclei at charge freezing conditions. In the iron group region, new seeds are also created for the r-process. In particular, the magnetic enhancement of the volume of 44Ti isotopes is consistent with results from observations and indicates the substantial increase in the abundance of the main titanium isotope (48Ti) in the Galaxy’s chemical composition. Magnetic effects are proven to result in a shift of the r-process path towards smaller mass numbers, as well as an increase in the volume of low-mass nuclides in peaks of the r-process nuclei.

Mineralogical and Chemical Specificity of Dusts Originating from Iron and Non-Ferrous Metallurgy in the Light of Their Magnetic Susceptibility

This study aims at detailed characteristics and comparison between dusts from various iron and non-ferrous metal production processes in order to identify individual mineral phases, chemical composition, and their influence on the values of magnetic susceptibility. Various analytical methods used include inductively coupled plasma optical emission spectroscopy, X-ray diffraction, scanning electron microscopy, and Mössbauer spectroscopy integrated with magnetic susceptibility measurements and thermomagnetic analysis. Metallurgical wastes that have arisen at different production stages of iron and non-ferrous steel are subjected to investigation. The analyzed dust samples from the iron and non-ferrous metallurgy differ in terms of magnetic susceptibility as well as their mineral and chemical composition. The research confirmed the presence of many very different mineral phases. In particular, interesting phases have been observed in non-ferrous dust, for example challacolloite, which was found for the first time in the dusts of non-ferrous metallurgy. Other characteristic minerals found in non-ferrous metallurgy dusts are zincite, anglesite, and lanarkite, while dusts of iron metallurgy contain mostly metallic iron and iron-bearing minerals (magnetite, hematite, franklinite, jacobsite, and wüstite), but also significant amounts of zincite and calcite.

Application of Mössbauer Spectroscopy for Identification of Iron-Containing Components in Upper Silesian Topsoil Being under Industrial Anthropopressure.

The main objective of the presented preliminary study was the identification of iron-containing phases. Iron-containing phases had accumulated in organic topsoil horizons collected from an area that has long been affected by the steel industry and emissions from power plants. X-ray diffraction and Mössbauer spectroscopy methods were used for the determination of the iron-containing mineral phases in topsoil subsamples which, after two-staged separation, varied in terms of magnetic susceptibility and granulometry. The Mössbauer spectra were recorded using paramagnetic and magnetic components, although the latter occurred only in the strongly magnetic fraction. The central part of spectra was fitted by two doublets (D1 and D2), which were identified as aluminosilicates. Simultaneously, the experimental spectra were described using several Zeeman sextets (Z1, Z2, and Z3) corresponding to the occurrence of hematite and magnetite-like phases with iron in tetrahedral and octahedral sites. Identification of magnetic phases in the tested material, including hematite, led to the conclusion that soil contamination in the studied area was presumably caused by emissions from a nearby power plant. Magnetite-like phases with a different iron content detected in topsoil samples could be related to metallurgical and coking processes, reflecting the specificity of the industrial area from which the samples were taken. The specific composition of the iron-containing aluminosilicates also illustrated the intense and long-lasting impact of the steel and coking industries on the studied area.

Metastable skyrmion lattices governed by magnetic disorder and anisotropy in β -Mn-type chiral magnets

Magnetic skyrmions are vortex-like topological spin textures often observed in structurally chiral magnets with Dzyaloshinskii-Moriya interaction. Among them, Co-Zn-Mn alloys with a $\beta$-Mn-type chiral structure host skyrmions above room temperature. In this system, it has recently been found that skyrmions persist over a wide temperature and magnetic field region as a long-lived metastable state, and that the skyrmion lattice transforms from a triangular lattice to a square one. To obtain perspective on chiral magnetism in Co-Zn-Mn alloys and clarify how various properties related to the skyrmion vary with the composition, we performed systematic studies on Co$_{10}$Zn$_{10}$, Co$_9$Zn$_9$Mn$_2$, Co$_8$Zn$_8$Mn$_4$ and Co$_7$Zn$_7$Mn$_6$ in terms of magnetic susceptibility and small-angle neutron scattering measurements. The robust metastable skyrmions with extremely long lifetime are commonly observed in all the compounds. On the other hand, preferred orientation of a helimagnetic propagation vector and its temperature dependence dramatically change upon varying the Mn concentration. The robustness of the metastable skyrmions in these materials is attributed to topological nature of the skyrmions as affected by structural and magnetic disorder. Magnetocrystalline anisotropy as well as magnetic disorder due to the frustrated Mn spins play crucial roles in giving rise to the observed change in helical states and corresponding skyrmion lattice form.

Properties and Composition of Magnetized Nuclei

The properties and mass distribution of the ultramagnetized atomic nuclei which arise in heavy-ion collisions and magnetar crusts, during Type II supernova explosions and neutron star mergers are analyzed. For the magnetic field strength range of 0.1–10 teratesla, the Zeeman effect leads to a linear nuclear magnetic response that can be described in terms of magnetic susceptibility. Binding energies increase for open shell and decrease for closed shell nuclei. A noticeable enhancement in theyield of corresponding explosive nucleosynthesis products with antimagic numbers is predicted for iron group and r-process nuclei. Magnetic enrichment in a sampleof 44Ti corroborate theobservational results and imply a significant increase in the quantity of the main titanium isotope, 48Ti, in the chemical composition of galaxies. The enhancement of small mass number nuclides in the r-process peak may be due to magnetic effects.

Effects of 3-D Printed Structural Characteristics on Magnetic Properties

Additive manufacturing, particularly 3-D printing, allows for completely customizable designs with relatively no limits on geometric complexities. In order to ensure optimal part design for potential magnetic applications, it is crucial to study how the different 3-D printer settings impact the magnetic properties of the printed part. Specifically, in this paper, it was determined how three structural print parameters (outer shell thickness, internal fill factor, and internal layer orientation) affect the resulting magnetic properties of 3-D printed cubic samples. The samples are made using fused deposition modeling of an iron–polymer composite filament. Hysteresis loops were gathered for fields applied along the [100], [110], and [001] directions of the printed cubes. From this, it was determined which combination of print settings should be used to achieve the most desirable magnetic response in terms of magnetic susceptibility, net magnetic moment, and mass-normalized saturation magnetization.

전암대자율을 이용한 여주 고달사지 원종대사탑비 비신의 복제용 석재 선정 연구

여주 고달사지 원종대사탑비는 과거 도괴되어 현재 귀부와 이수는 여주 고달사지에 남아있고 비신은 파손된 채 국립중앙박물관에 보관되어 있다. 탑비를 구성하는 암석은 두 종류로, 귀부와 이수는 조립질 흑운모화강암, 비신은 부분적으로 각섬석 집합체와 2~3 cm 크기의 장석반정이 특징적으로 관찰되는 세립질 흑운모화강암이다. 귀부와 이수의 조립질 흑운모화강암은 여주 일대에 분포하는 흑운모화강암과 전암대자율 및 암석기재적 특징이 매우 유사하다. 반면 비신의 암석은 이 지역 내에서 산출되는 암석과 다소 차이가 있어 국내 화강암의 전암대자율, 암석학적 특징, 탑비의 금석문과 고려시대 고문헌 기록을 토대로 유사한 암석의 산출지를 탐색하였다. 이 결과 북한 해주 지역의 화강암이 색상, 각섬석 집합체, 광물조성, 전암대자율 분포 등에 있어 비신의 세립질 흑운모화강암과 거의 동일하였다. 따라서 해주 화강암이 탑비 암석의 산지암석으로서 가능성이 가장 크며, 원종대사탑비 비신을 복제하기 위한 석재로 가장 적합한 것으로 판단된다. The Stele for Buddhist Monk Wonjong at Godalsa Temple Site was destroyed a long time ago. Only the tortoise-shaped pedestal and the ornamental capstone in the form of a hornless dragon remain at the site and the broken stele body is stored at the National Museum of Korea today. The stele is made of two kinds of rocks that are coarse-grained biotite granite for the pedestal and the capstone, and fine-grained biotite granite including hornblende assemblages and feldspar phenocrysts for the stele body. The coarse-grained biotite granite of the pedestal and capstone showed same magnetic susceptibility and lithological characteristics with biotite granite outcrops in Yeoju area, whereas the fine-grained granite of the stele body did not. To find a provenance of the stele body stone, we investigated Korean granites in terms of magnetic susceptibility, lithology and old recordings about construction process of the stele. As a result, Haeju granite is the most likely to be a cognate rock of the stele body stone as it has same texture and lithological characteristics like color, hornblende assemblages, mineral composition and magnetic susceptibility. It is imported from Haeju (North Korea) to South Korea via China commercially, and the most suitable for a replica stone of the stele body.

Nickel(II) complexes with bridged polyamines

Three nickel(II) complexes [Ni2(μ-trien)(trien)2](ClO4)4 (1), {[Ni2(μ-tren)2(tren)](ClO4)4·3,25H2O}n (2) and [Ni3(μ-tren)2(tren)2(H2O)2]Cl6·2H2O (3) (trien=N,N′-bis(2-aminoethyl)ethane-1,2-diamine, tren=N,N′-bis(2-aminoethyl)-1,2-ethanediamine) were synthesized and structurally characterized. Complex 1 consists of dimeric [Ni2(μ-trien)(trien)2]4+ cation and perchlorate anions, compound 2 contains polymer chain of cation {[Ni2(μ-tren)2(tren)]4+}n, perchlorate anions and uncoordinated water molecules, and structure of 3 consists of [Ni3((μ-tren)2(tren)2(H2O)2]6+ cation, chloride anions and uncoordinated water molecules. All compounds exhibit octahedrally coordinated nickel atoms. Two nickel(II) atoms of [Ni2(μ-trien)(trien)2]4+ cation in 1 are bridged through one trien ligand, which is bidentate to both nickel(II) atoms. The central Ni(II) atom in complex 3 is associated with peripheral atoms with one arm of tren ligand bonded in tridentate fashion, similarly as two nickel(II) atoms in polymer of complex 2. The magnetic behaviour of 1 and 2 complexes have been investigated in terms of magnetic susceptibility and magnetization. The magnetic analyses confirmed weak antiferromagnetic exchange between paramagnetic Ni(II) centres. The experimental observations were further confirmed and studied by DFT method at B3LYP/def2-TZVP level of theory for all compounds.

Structural and magnetic properties of Cr+3doped nano-structuredγ-Fe2O3synthesized by a modified solution combustion technique

Chromium doped gamma ferrite nanopowders (16.91 nm to 25.61 nm) of the composition (Fe 2- x Cr x O 3 for x = 0.00, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10) were successfully synthesized by a modified solution combustion method using citric acid as fuel at a temperature as low as 150 °C. The so prepared samples were examined by powder XRD for phase identification and crystallite size determination. The dimensions of particle size as calculated from XRD are in good agreement with those evaluated by transmission electron microscope (TEM). Fourier Transform Infrared (FTIR) analysis was carried out to identify the various chemical bonds present in the system. Magnetic examinations were performed in terms of magnetic susceptibility and hysteresis plots. A decrease in the blocking temperature with the increase of dopant concentration was observed which is explained on the basis of Neel's relaxation theory. A simple model has been suggested to explain the behaviour of hysteresis trends as the function of dopant concentration.

Granitoid Series in Terms of Magnetic Susceptibility: A Case Study from the Barberton Region, South Africa

Magnetic susceptibilities were measured on a representative collection of Archaean granitoids of the Barberton region using a portable KT5 magnetic susceptibility meter. The studied granitoids comprise, (1) syn-tectonic tonalite-trondhjemite-granodiorite (TTG) granitoids (132 samples), (2) late-tectonic calc-alkaline granitoids (402 samples) and (3) post-tectonic low-Ca and high-Ca granitoids (12 samples). Most of the early-stage syn-tectonic granitoids (∼3450 Ma) have low magnetic susceptibilities, less than 3 × 10 −3 SI units, and correspond to ilmenite-series granitoids. The late-stage Kaap Valley tonalite pluton (∼3230 Ma) contains sporadically distributed higher magnetic susceptibility values (greater than 3 × 10 −3 SI units), which are less than one-third in magnetic susceptibility of typical magnetite-series TTG of the Japanese Island Arc and thus strictly belong to an intermediate series. The Barberton TTG suite is essentially derived from reduced amphibolitic lower crust that reflects the anoxic nature of the Earth surface during the Archaean Eon. The more oxidized nature of the Kaap Valley tonalite may be generated in an oxidized lower crust by fluids squeezed out of the subducting plate. Late-tectonic granodiorite - adamellite batholithic complexes (∼3105 Ma) belong mostly to the magnetite series, and seem to suggest that relatively oxidized continental crust, reflecting oxic atmosphere and subduction mechanism operating, had evolved it by this time. Post-tectonic granitic plutons formed largely between circa 2900 Ma and 2700 Ma can be subdivided into low-Ca ilmenite series and high-Ca magnetite series.

Giant magneto-impedance effects in Metglas 2705M

Giant magneto-impedance (GMI) results for Metglas 2705M have been studied in two measuring geometries in several field annealed samples. A rich variety of peak features in GMI, all within a small field range, have been observed. The various features in the GMI are discussed in terms of magnetic susceptibility and microstructural properties of the amorphous ribbon.

Towards the in situ measurement of the remanent magnetization of oceanic basalts

SUMMARY Recent developments in electromagnetic double dipole devices make these systems convenient for both magnetic susceptibility and resistivity measurements. The coupling of such an electromagnetic logging tool with a magnetic probe supplying the three components of the total magnetic field in the well, allows in siru determination of magnetic parameters. This paper shows how to (i) interpret the raw data in terms of magnetic susceptibility and resistivity of the surrounding medium (ii) determine the horizontal and vertical components of the total magnetization, and (iii) separate the remanent magnetization which seems to be possible at many points of the logging.

Physical basis of the effect of hemoglobin on the 31P NMR chemical shifts of various phosphoryl compounds.

The marked difference between the intra- and extracellular 31P NMR chemical shifts of various phosphoryl compounds when added to a red cell suspension may be largely understood in terms of the effects of hemoglobin on the 31P NMR chemical shifts. The presence of [oxy- or (carbonmonoxy)-] hemoglobin inside the red cell causes the bulk magnetic susceptibility of the cell cytoplasm to be significantly less than that of the external solution. This difference is sufficient to account for the difference in the intra- and extracellular chemical shifts of the two phosphate esters trimethyl phosphate and triethyl phosphate. However, in the case of the compounds dimethyl methylphosphonate, diethyl methylphosphonate, and trimethyl-phosphine oxide as well as the hypophosphite, phenylphosphinate, and diphenylphosphinate ions, hemoglobin exerts an additional, much larger, effect, causing the 31P NMR resonances to shift to lower frequency in a manner that cannot be accounted for in terms of magnetic susceptibility. Lysozyme is a protein structurally unrelated to hemoglobin and was shown to cause similar shifts to lower frequency of the resonances of these six compounds; this suggests that the mechanism may involve a property of proteins in general and not a specific property of hemoglobin. The effect of different solvents on the chemical shifts of the eight phosphoryl compounds provided an insight into the possible physical basis of the effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Identification and properties of ultra-fine iron particles dispersed in a glass-like carbon matrix

Various kinds of iron particles and an iron species were synthesized from acetylferrocenefurfural resins in a glass-like carbon matrix by heat-treatment. These irons were investigated in terms of magnetic susceptibility, saturation magnetization, esr, and the Mossbauer effect. Body-centred cubic (b c c) iron, expanded b c c iron, hexagonal close-packed iron, and cluster iron were present as ultra-fine iron particles. The presence of Fe+ was well established as an iron species. The formation of iron particles and Fe+ is discussed on the basis of the pyrolysis of ferrocene skeletons in the resin.