Search for dissertations about: "maghemite"

Showing result 1 - 5 of 9 swedish dissertations containing the word maghemite.

  2. 1. Interacting Magnetic Nanosystems : An Experimental Study Of Superspin Glasses

    Author : Mikael Svante Andersson; Roland Mathieu; Dino Fiorani; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; spin glass; SQUID magnetometry; maghemite; magnetism; nanoparticles;

    Abstract : This thesis presents experimental results on strongly interacting γ-Fe2O3 magnetic nanoparticles and their collective properties. The main findings are that very dense randomly packed (≈60%) γ-Fe2O3 nanoparticles form a replica of a spin glass. READ MORE

  4. 2. Nanomagnetic and Micromagnetic Properties of Rocks Minerals and Sulphide Oxidation Products

    Author : Erik Eneroth; Berggrundsgeologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; physical geography; Geology; multi-domain; single-domain; ilmenite; magnetite; maghemite; hematite; pyrite; marcasite; fysisk geografi; Geologi;

    Abstract : Magnetic and related properties of rocks and products from oxidation of sulphide minerals have been investigated with magnetisation measurements (rocks and oxidation products), magnetic force microscopy (rocks), scanning electron microscopy (rocks and oxidation products), transmission electron microscopy (oxidation products), Mössbauer spectroscopy (oxidation products) and powder X-ray diffraction (oxidation products). The investigations have shown the following: During thermal oxidation of pyrite (cubic FeS2) and marcasite (orthorombic FeS2) in air, nano-crystals of a-Fe2O3 and g-Fe2O3 were formed. READ MORE

  5. 3. Reactions at the water-mineral interface of olivine and silicate modified maghemite

    Author : Rickard Jolsterå; Luleå tekniska universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Chemistry of Interfaces; Gränsytors kemi;

    Abstract : The main objectives for this licentiate thesis have been to study and model the reactions at the water-mineral interface of two subsystems: maghemite-H+-silicate and olivine-H+. An increased knowledge of these systems will make it possible to further extend the complexity of the aqueous phase in future experiments. READ MORE

  6. 4. Surface reactions of magnetite and maghemite with dissolved and added ions in process water

    Author : Rickard Jolsterå; Jean-Francois Boily; Luleå tekniska universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Chemistry of Interfaces; Gränsytors kemi;

    Abstract : Reactions between mineral surfaces and dissolved species in process water, both inorganic and organic play an important role in mineral processing. Reverse flotation of finely comminuted iron ore is sometimes employed in order to remove the phosphorous mineral apatite. READ MORE

  7. 5. Characterisation and surface reactions of iron oxides and fluorapatite in aqueous suspensions

    Author : Mathias Jarlbring; Luleå tekniska universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Chemistry of Interfaces; Gränsytors kemi;

    Abstract : The final objective of this study is to produce chemical models of flotation- like systems, including oxidation products of magnetite (maghemite and hematite) together with apatite. This is started by investigating the acid base properties, surface complexation and surface characteristics of the systems hematite-H+ and maghemite-H+ (paper I), fluorapatite-OH- (paper II) and a mixed system of maghemite-fluorapatite-OH- (paper III). READ MORE