Showing papers by "University of Ioannina published in 1973"
TL;DR: In this article, a soil of Attica (Greece) has been studied by M6ssbauer spectroscopy and magnetization measurements in order to ascertain the nature and form of iron oxides present in it.
Abstract: A soil of Attica (Greece) has been studied by M6ssbauer spectroscopy and magnetization measurements in order to ascertain the nature and form of iron oxides present in it. The room tempera- ture spectra consist of a paramagnetic doublet and a small magnetic sextet. At liquid nitrogen tempera- ture the magnetic component increases considerably at the cost of the paramagnetic component. This behavior is typical of superparamagnetism exhibited by ultrafine magnetic particles. From the values of hyperfine parameters extracted by computer fits of the spectra, the particles can be identified mainly as a-Fe203. The theory of superparamagnetism, in conjunction with M6ssbauer and magnetiza- tion data, is discussed in detail. Application of this theory to the data for the clay fraction of the soil leads to the conclusion that the oxide particles have a size distribution with a mean particle diameter of 131 A and a width of 14 A.
69 citations
TL;DR: In this paper, a synchronization system for Mossbauer spectroscopy is described which removes some of the disadvantages of existing systems and can be easily assembled with commercially available integrated circuit components.