caa a22 4500 445299886 CHVBK 20180317142554.0 cr unu---uuuuu 170323e20100701xx s 000 0 eng 10.1007/s11430-010-4015-y doi (NATIONALLICENCE)springer-10.1007/s11430-010-4015-y Effects of the grain size distribution on the temperature-dependent magnetic susceptibility of magnetite nanoparticles [Elektronische Daten] [XiangYu Zhao, QingSong Liu] Magnetite is an important magnetic remanence carrier in natural samples and therefore is of great interest in paleo-, rock-, and environmental magnetism. The magnetic properties of magnetite depend on many factors, e.g., concentration and grain size distribution (GSD). In this study, we theoretically investigated the temperature-dependent susceptibility (TDS) of magnetite nanoparticles with a lognormal GSD. Results show that the TDS is affected highly by the GSD mainly in three aspects. Firstly, the unblocking process becomes smoother with the increase of distribution width, characterizing as a wider Hopkinson peak on the TDS curve. Secondly, the blocking temperature increases with the increase of the median diameter or/and the distribution width. Thirdly, the maximum susceptibility decreases with the increase of distribution width, and has a logarithmic function relation with the standard deviation of the distribution. As a case study, this model was further applied to the thermal products of the Chinese loess/paleosol samples to determine the granulometry of newly-formed magnetite upon heating based on TDS curves. The results demonstrate the fidelity and feasibility of this method to determine the GSD of nano-sized magnetic particles. Science China Press and Springer-Verlag Berlin Heidelberg, 2010 Néel theory nationallicence temperature dependence of susceptibility nationallicence grain size distribution nationallicence Zhao XiangYu Paleomagnetism and Geochronology Laboratory (SKL-LE), Institute of Geology and Geophysics, Chinese Academy of Sciences, 100029, Beijing, China aut Liu QingSong Paleomagnetism and Geochronology Laboratory (SKL-LE), Institute of Geology and Geophysics, Chinese Academy of Sciences, 100029, Beijing, China aut Science China Earth Sciences SP Science China Press 53/7(2010-07-01), 1071-1078 1674-7313 53:7<1071 2010 53 11430 https://doi.org/10.1007/s11430-010-4015-y text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11430-010-4015-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Zhao XiangYu Paleomagnetism and Geochronology Laboratory (SKL-LE), Institute of Geology and Geophysics, Chinese Academy of Sciences, 100029, Beijing, China aut NATIONALLICENCE 700 1- Liu QingSong Paleomagnetism and Geochronology Laboratory (SKL-LE), Institute of Geology and Geophysics, Chinese Academy of Sciences, 100029, Beijing, China aut NATIONALLICENCE 773 0- Science China Earth Sciences SP Science China Press 53/7(2010-07-01), 1071-1078 1674-7313 53:7<1071 2010 53 11430 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer