共查询到20条相似文献,搜索用时 46 毫秒
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Bustamante A. Montoya J. Delgado M. Scorzelli R. B. Rossi A. M. Poupeau G. 《Hyperfine Interactions》2003,150(1-4):73-89
We report on an investigation of several ancient clays which were used for pottery making in northern coastal Peru at a kiln site from the Formative period (ca. 2000–800 BC) in the Poma Canal and at a Middle Sicán pottery workshop in use between ca. AD 950 and 1050 at Huaca Sialupe in the lower La Leche valley. Neutron activation analysis, 57Fe Mössbauer spectroscopy and X-ray diffraction were used for the characterisation of the clays. The changes that occur in iron-bearing compounds in the clays depending on the kiln atmosphere and on the maximum firing temperature were studied by Mössbauer spectroscopy and X-ray diffraction. Laboratory firing series under varying controlled conditions were performed to obtain a basic understanding of the different reactions taking place in the clays during firing. The results can be used as models in the interpretation of the Mössbauer spectra observed in ancient ceramics from the same context. 相似文献
3.
Yuanfu Hsia Zhengfang Hu Rongchuan Liu Qi Zeng Zhengfang Yu Yufang Zheng 《Hyperfine Interactions》1988,41(1):803-806
18 Sherds (4500 B.C.–4000 B.C.) unearthed from different archaeological layers at the same place were studied by Mössbauer spectroscopy. The original firing atmosphere can be deduced from the ratio of the Fe2+ to Fe3+. By comparing the Mössbauer parameters of the original and the refired sherds, we can assess the original firing temperatures. 相似文献
4.
J. Lipka J. Rausz M. Gajdošová G. Fusek J. Sitek M. Hucl 《Hyperfine Interactions》1990,57(1-4):2257-2260
Ancient pottery samples collected from south-west Slovakia were studied through subjective observation and by Mössbauer spectroscopy. This method is convenient for determining the provenance and the manufacture of pottery. Transformations, induced by firing the clay and characterized by Mössbauer spectroscopy, give valuable information regarding the manufacture as, for instance, the final temperature of firing in it. The relative abundance of Fe2+ and Fe3+ determines the atmosphere used to fire a pottery. It has been found that the determination of the firing atmosphere obtained through the subjective observation is in good agreement with that obtained using Mössbauer spectroscopy. An unfired and fired clay was also investigated. 相似文献
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R. R. Gainov F. G. Vagizov V. A. Golovanevskiy V. A. Ksenofontov G. Klingelhöfer V. V. Klekovkina T. G. Shumilova I. N. Pen’kov 《Hyperfine Interactions》2014,226(1-3):51-55
Nuclear resonance methods, including Mössbauer spectroscopy,are considered as unique techniques suitable for remote on-line mineralogical analysis. The employment of these methods provides potentially significant commercial benefits for mining industry. As applied to copper sulfide ores, Mössbauer spectroscopy method is suitable for the analysis noted. Bornite (formally Cu5FeS4) is a significant part of copper ore and identification of its properties is important for economic exploitation of commercial copper ore deposits. A series of natural bornite samples was studied by 57Fe Mössbauer spectroscopy. Two aspects were considered: reexamination of 57Fe Mössbauer properties of natural bornite samples and their stability irrespective of origin and potential use of miniaturized Mössbauer spectrometers MIMOS II for in-situ bornite identification. The results obtained show a number of potential benefits of introducing the available portative Mössbauer equipment into the mining industry for express mineralogical analysis. In addition, results of some preliminary 63,65Cu nuclear quadrupole resonance (NQR) studies of bornite are reported and their merits with Mössbauer techniques for bornite detection discussed. 相似文献
6.
57Fe Mössbauer spectroscopy reveals changes in iron valence and iron site geometry when clays and clay minerals are heated, and allows a distinction to be made between paramagnetic and magnetically ordered phases. Mössbauer spectra can thus reveal the extent of iron retention in silicate structures upon heating, the identity of iron oxides initially present or formed during the heating process and their transformations, and the character of the atmosphere under which heating was carried out. This makes Mössbauer spectroscopy the most effective tool for the characterization of changes induced by heating phyllosilicates and iron oxides. 相似文献
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U. Wagner F. E. Wagner A. Stockklauser R. Salazar J. Riederer F. Kauffmann-Doig 《Hyperfine Interactions》1986,29(1-4):1113-1116
A large number of ceramic sherds from Chavin, Peru, as well as recent clay samples from the same region have been studied by Mössbauer spectroscopy. The changes of the Mössbauer spectra of the clay were studied as a function of firing temperature and atmosphere. From a comparison of these data with those form the sherds one can make estimates of the precolumbian firing conditions. 相似文献
8.
The physical, chemical and mineralogical aspects of the use of Mössbauer spectroscopy in studies of clay-based ceramics are described. Mössbauer spectra of pottery clays fired under oxidising, reducing and changing conditions are explained, and the possibilities of using Mössbauer spectra to derive information on the firing temperatures and the kiln atmosphere during firing in antiquity are discussed and illustrated by examples. 相似文献
9.
Kuno A. Zheng G. D. Matsuo M. Takano B. Shi J. A. Wang Q. 《Hyperfine Interactions》2002,141(1-4):321-326
In this study, 57Fe Mössbauer spectroscopy has been applied to sediments collected from Qinghai Lake in Qinghai Province, China, to investigate the vertical distribution of iron species. Their Mössbauer spectra consisted of four doublets ascribable to one paramagnetic high-spin Fe3+, two paramagnetic high-spin Fe2+ with different quadrupole splittings, and one diamagnetic low-spin Fe2+ that corresponds to pyrite (FeS2). The distribution of pyrite suggested climatic changes during the past nine thousand years. It was demonstrated that the iron speciation in the salt lake sediments by Mössbauer spectroscopy can be used to reconstruct the past environment.
相似文献10.
Frans B. Waanders Antoinne F. Mulaba-Bafubiandi Lonzeche Lodya 《Hyperfine Interactions》2014,226(1-3):721-735
South Africa is a country that is very rich in mineral resources but the use of Mössbauer spectroscopy to solve operational industrial problems is however very limited. In the Bushveld Igneous Complex the main minerals extracted from the ore are the platinum group metals and chromium, but secondary recovery of base metals such as nickel, copper and cobalt forms an integral part of the process. Losses of nickel in the slag can amount to about 4 % and subsequent a slag cleaning furnace is used to reduce the loss to less than 0.5 % nickel oxide. The Fe2+/Fe3+ ratio and mineralogy was used to determine the partial oxygen pressure in the furnaces and also the efficiency of the nickel recovery. From the Mössbauer results, augmented with XRD, SEM, EMP-WDX and MLA analyses, optimum conditions were determined to ensure minimum metal losses. The use of Mössbauer spectroscopy in the coal industry, to investigate mineral changes that occur during its use, is also of importance. The main minerals present in coal were determined with the aid of various techniques, such as Mössbauer, XRD, SEM and HR-TEM, with the major iron minerals found to be pyrite, illite, ankerite and jarosite. A large quantity of coal is used to produce syngas via gasification plants for the production of synthetic fuels. The change of the mineral matter during gasification was studied and the changes occurring during the gasification process were followed. The syngas produced, is further treated by means of the Fischer–Tropsch process where an iron catalyst is incorporated in the process. The usefulness and fouling of the catalyst is being studied with the aid of Mössbauer spectroscopy. The calibration of equipment to determine work hardening in mining equipment was also investigated and found to be a useful tool in industry. From the above few examples it is evident that, although used on a limited base, Mössbauer spectroscopy, augmented by various other spectroscopic tools, still ensures optimal recovery and production of the vast resource base of South Africa. 相似文献
11.
We have succeeded in precisely determining the hyperfine interactions, particularly the isomer shifts, in the 149Sm Mössbauer transition. The difference in the nuclear radii between the ground and excited states is critical for the determination of isomer shifts but is relatively small in 149Sm. Therefore, the precise determination by 149Sm Mössbauer spectroscopy is difficult. The recent development of synchrotron-radiation-based Mössbauer spectroscopy allows the isomer shifts to be determined more precisely than previously with the help of wellcollimated synchrotron radiation. In particular, the time-window effect assists the precise determination of hyperfine interactions in the 149Sm Mössbauer transition because this effect enables us to measure spectra with higher energy resolution than natural linewidth determined by the lifetime of the excited states. Meanwhile, highenergy-resolution measurements to determine center shifts by SR-based Mössbauer spectroscopy enable us to observe the second-order Doppler shift, which has not been discussed, particularly for heavy Mössbauer nuclei. We have discussed the precise determination of isomer shifts and the observation of the second-order Doppler shift using 149Sm synchrotron-radiation-based Mössbauer spectroscopy. 相似文献
12.
The Mössbauer spectroscopy was applied to study radiation damage in metal-metalloid amorphous alloys irradiated with40Ar/E=225 MeV/ or132Xe/E=120 MeV/ ions at room temperature. The observed dose dependent changes in the intensity of the Mössbauer lines and of the hyperfine field distributions can be associated with structural changes in short-range order of the irradiated amorphous alloys. 相似文献
13.
Mössbauer spectroscopy is highly suited for the study of clays whose industrial uses depend on the iron content. Reactions that take place during clay firing can be readily monitored by Mössbauer spectroscopy. Following dehydroxylation of clay minerals, the quadrupole splitting of octahedrally coordinated iron (III) increases abruptly, but reverts to lower values upon the formation of new, better ordered phases at higher temperatures. It is also shown that iron oxides may account for a considerably higher proportion of the total iron content of many clays than is commonly recognized, and their existence must be taken into consideration for a correct interpretation of the Mössbauer spectra of clays. 相似文献
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E. Kuzmann S. Stichleutner A. Sápi Z. Klencsár M. I. Oshtrakh V. A. Semionkin S. Kubuki Z. Homonnay L. K. Varga 《Hyperfine Interactions》2013,215(1-3):63-67
Stress field and magnetic field annealed FINEMET ribbons were investigated by 57Fe Mössbauer spectroscopy, magnetic and XRD methods. The change in relative areas of the 2nd and 5th lines in the Mössbauer spectra indicated significant variation in magnetic anisotropy due to the different annealing. High velocity resolution Mössbauer spectroscopy was also used to control the model applied for the evaluation of Mössbauer spectra. A correlation was found between the permeability and the magnetic anisotropy of the annealed FINEMET samples. This can be applied to predict production parameters of FINEMET ribbons with more favorable soft magnetic properties for technological applications. 相似文献
15.
Mössbauer spectroscopy has proven itself to be invaluable to archaeologists by providing a means to classify pottery and to provide information on particular providences for various ancient pottery finds. The original firing atmosphere can often by deduced from the ratio of Fe2+ to Fe3+. The change in the quadrupole splitting and the magnetic hyperfine splittings allow for the determination of the original firing temperatures. Ancient pottery samples from many cultures have been studied and a number of general conclusions are possible. 相似文献
16.
The effects of firing atmosphere parameters on the microstructural characteristics and physical properties of clay roofing tiles were studied. For these investigations, 57Fe Mössbauer spectroscopy, X-ray diffractometry and dilatometry were used. XRD of the raw material exploited from the clay pit belonging to the roofing tile factory “Potisje-Kanjiza”, revealed the presence of montmorillonite, kaolinite, illite and some chlorite clay minerals, as well as, quartz, albite, calcite and dolomite. Gradual changes were observed both in the 57Fe Mössbauer spectra and X-ray diffractograms with samples fired in reducing CO/N2 gas atmosphere at temperatures between 700 and 1060 °C. These changes reflect the dehydroxylation processes, oxide (Fe3O4) formation, carbonate decomposition, densification and new silicate (plagioclase) formation. The firing conditions in reducing atmosphere were determined to produce roofing tiles with improved properties. 相似文献
17.
Farit Vagizov Roman Kolesov Silviu Olariu Yuri Rostovtsev Olga Kocharovskaya 《Hyperfine Interactions》2006,167(1-3):917-921
We report the first observation of a laser-produced vibration with the aid of Mössbauer techniques. Thin platelets of MgO single crystals were doped by diffusion of 57Fe atoms. The illumination of the MgO:57Fe sample with a pulsed Nd:YAG laser produced a significant broadening of the Mössbauer spectrum. In order to find out what caused these changes, we performed a series of time-domain experiments, in which the Mössbauer spectra were collected only during a 2.5 μs gate interval. This gate interval was swept from 5 μs to 190 μs over the time interval between the two laser pulses. After laser irradiation, the position of the Mössbauer line was found to be changing in time as a decaying oscillations of well-defined frequency, which can be due to the vibration of the sample induced by the laser pulse. 相似文献
18.
Glycerol forms a molecular glass near 180K. Fe2+ dissolved in glycerol allows the study of the dynamics of the system by Mössbauer spectroscopy. Recently it has been shown that the Mössbauer spectra can be understood in a way consistent with the results of dielectric and ultrasonic viscoelastic relaxation measurements. A jump diffusion model of Sinqwi and Sjolander with a jump rate distribution according to Davidson and Cole allowed us to fit the Mössbauer spectra of Fe in glycerol. First attempts to compare mode coupling theory with Mössbauer spectra are reported. 相似文献
19.
U. Wagner F. E. Wagner B. Marticorena R. Salazar R. Schwabe J. Riederer 《Hyperfine Interactions》1986,29(1-4):1117-1120
To obtain information on the firing of inca ceramics, 7 samples from different locations were studied by Mössbauer spectroscopy including a detailed laboratory refiring procedure. The glaze typical for the surface of this ware was studied by Mössbauer scattering. 相似文献
20.
E. Kuzmann K. Nomura M. El-Sharif C.U. Chisholm G. Principi C. Tosello R. Gupta K. Havancsak A. Vértes 《Hyperfine Interactions》1998,112(1-4):175-178
Electrodeposited Fe-Ni-Cr alloys irradiated with 209 MeV energy 84Kr ions were investigated by conversion electron Mössbauer spectroscopy, X-ray diffraction and electron microprobe analysis. Significant dose dependent changes were found between Mössbauer spectra of the irradiated and non-irradiated deposits. These changes reflect the dose dependent transformation of the metastable ferromagnetic phase to the paramagnetic one. 相似文献