Authors:Y. Kobayashi, M. Katada, H. Sano, T. Okada, K. Asai, and F. Ambe
99Ru and57Fe-Mössbauer spectroscopic and magnetization measurements were made in order to clarify the magnetic properties of a Huesler alloy, RuFe2Si. The result obtained from99Ru-Mössbauer spectrum leads to the conclusion that Ru atoms were substituted by both Fe[A, C] and Fe[B], but the latter preferentially.
The random bound mixed compound Fe(Br0.8I0.2)2has been investigated by magnetization and Mössbauer spectroscopy. The experimental results for Fe(Br0.8I0.2)2were compared with those of Fe(Br0.6I0.4)2studied previously. A magnetic structure below the magnetic transition temperature observed by Mössbauer spectroscopy has
been suggested which shows a large distribution ofthe hyperfinefields.
Authors:S. Talapatra, T. Kim, B. Q. Wei, S. Kar, R. Vajtai, G. V. S. Sastry, M. Shima, D. Srivastava, and P. M. Ajayan
on the room temperature ferromagnetism observed in heat treated nanocrystalline
diamonds. By systematic annealing of nanocrystalline diamond, graphitic
nanoclusters having finite magnetization with well-defined hysteresis and
coercivity, and a Curie temperature (TC) well above 400 K (estimated TC ~ 590
K), were synthesized. Using detailed analysis of the structural modification at
various annealing stages, with Raman Spectroscopy and High Resolution
Transmission Electron Microscopy, we show that the carbon bonding configuration
has important consequence to the observed magnetism in these samples. These
findings could lead to controlled fabrication of metal free magnetic carbon
The objective of present research was to sinter nanosized Mn–Zn ferrites (MZF) at low temperature (≤1,000 °C) by avoiding
the formation of nonmagnetic phase (hematite). For this purpose, MZF powder was synthesized by sol–gel auto combustion process
at 220 °C and further calcined at 450 °C. In calcined powder, single phase (spinel) was confirmed by X-ray diffraction analysis.
Pellets were pressed, having 43% of the theoretical density and showing 47 emu gm−1 saturation magnetization (Ms). Various combinations of heating rate, dwelling time and gaseous environment were employed to meet optimum sintering conditions
at low temperature (≤1,000 °C). It was observed that sintering under air or N2 alone had failed to prevent the formation of nonmagnetic (hematite) phase. However, hematite phase can be suppressed by retaining
the green compacts at 1,000 °C for 180 min in air then further kept for 120 min in nitrogen. Under these conditions, spinel
phase (comprising of nano crystallites), 90% of theoretical density and 102 emu gm−1 of saturation magnetization has been achieved.
Authors:Emõ Márton, Tibor Zelenka, and Péter Márton
Paleomagnetic measurements were carried out on 163 independently oriented samples from 19 sites of the Bükk Mts and their northern, western and southern forelands. The aim was to correlate the sites with one of three Miocene rhyolite tuff horizons using the combination of paleomagnetic marker horizons (rotational events) and traditional magnetostratigraphy.
In contrast to the results of earlier studies in the southern Bükk foreland, which yielded only reversed polarity magnetizations, nearly half of the presently obtained paleomagnetic directions are of normal polarity. By their declinations they mostly belong to the middle tuff horizon, and only one belongs to the upper.
The paleomagnetic age assignment of the studied sites sometimes supports one or both of the classifications of Balogh (1964) and Pelikán et al. (2005). However, about one-third of the sites classified by these authors as upper or lower tuffs were shown to belong to the middle tuff complex.
Thermal decomposition of managanese hexa(formato)ferrate(III)hexahydrate, i.e., Mn3[Fe(HCOO)6l2·6H2O has been studied upto 700°C in static air atmosphere employing TG, DSC, XRD, IR and Mössbauer spectroscopic techniques. The anhydrous complex decomposed directly into ferric oxide and manganese carbonate in successive stages without undergoing reduction to iron(II) intermediate. Finally a solid state reaction between Fe2O3 and manganese carbonate leads to the formatin of manganese ferrte (MnFe2O4) at a temperature (655°C) much lower than for ceramic method. A saturation magnetization value (4 Ms) of 2550 Gauss makes MnFe2O4 suitable for functioning at high frequencies.
Authors:Emő Márton, Davor Pavelić, Bruno Tomljenović, Péter Márton, and Radovan Avanić
This paper summarizes the paleomagnetic results that have
been obtained for the Neogene of the Croatian part of the Pannonian Basin since
1995. The paleomagnetic investigations were carried out almost exclusively on
sediments, which were deposited in widely differing environments. Most of the
paleomagnetic directions can be considered as of pre-folding age, but some were
clearly acquired diagenetically or even after deformation. This means that any
future magnetostratigraphic study in the southern Pannonian Basin must be
carried out with utmost care. Fortunately, the tectonic interpretation of the
data is favorably affected by the fact that magnetizations of pre and
post-folding ages show the same angles of declinations. They suggest that the entire
Croatian part of the Pannonian Basin rotated counterclockwise, by about 30°,
after the Early Pontian and before the Holocene. It is also remarkable that
Ottnangian data from the Slavonian Mts do not indicate a Tisia-type clockwise
rotation during the mid-Miocene.
Authors:Gyula Szöőr, Péter Rózsa, Bart Vekemans, László Vincze, Freddy Adams, Imre Uzonyi, Árpád Z. Kiss, and Imre Beszeda
Impact material, especially magnetizable tiny grains (spherules, globules and platelets) of Barringer Meteor Crater (Arizona) was studied by combined nuclear analytical techniques. The samples were analyzed first by micro-proton-induced X-ray emission (PIXE) and deuteron-induced gamma-ray emission (DIGE) methods. In this way it was possible to determine the distribution of elements down to carbon. Using micro-synchrotron radiation X-ray fluorescence technique (SRXRF) we could determine medium and high atomic number trace elements such as the platinum-group metals. Our methodological developments made it possible for the first time to carry out quantitative analysis for more than 40 elements, providing new perspectives for the interpretation of the impact materials. Various compositions of the findings around the Barringer Crater were compared to analytical data of similar objects found in Carpathian Basin to elucidate their origin. This paper summarizes the more important results obtained by using ion beam microanalytical techniques.
Authors:Yang Zhao, Liang Zhao, Xing Wei, Buxing Han, and Haike Yan
The enthalpies of solution of potassium chloride (KCl) in water and magnetically treated water (magnetized water) have been
measured at 298.15 K using a LKB-8700 precision solution calorimeter. From the experimental results, it was observed that
the effect of magnetic field on the enthalpy of solution is measurable. This is probably due to the distortion of the hydrogen
bond of water resulting from magnetic treatment.