The major issue concerns how the different lignosulfonate types changes the rheological properties of the cement based material (concrete, mortar and cement paste) as a function of temperature and time. In such terms, it is demonstrated that the high molecular weight lignosulfonates performs far better than the low molecular weight ones. The former type also performs considerable better compared to a naphthalene based polymer. The above investigation is done with help from the second part of this thesis, which identifies some of the parameters p1, p2,... affecting the shear viscosity η = η ( p1, p2,...) of the cement based material. This is done by investigating the thixotropic behavior of cement paste mixed with either lignosulfonates or naphthalene. The thixotropic behavior is directly related to coagulation, dispersion and re-coagulation of the cement particles. In making the analysis, a modification is applied to the Hattori-Izumi theory, which is a theory about the bookkeeping of the number of reversible coagulated connections between the cement particles. The modification consist, among other things, of include a fading memory to the analysis. That is, the cement paste is allowed to remember its recent past. By a combination of experimental results and numerical simulations, it is demonstrated that such memory term is very important. An experimental error is present during a viscometric measurement on concrete (a coaxial cylinders viscometer is used). The error is generated by particle migration. Investigating and compensating for this error constitutes the third part of this thesis. Realizing the nature of this error, some corrections are applied. However, with these corrections, one is only extracting the viscometric values of a "fat'' concrete that surrounds the inner cylinder of the viscometer after the particle migration is basically complete, and not of the concrete in the original homogenous state.

This work focuses on the surface and interfacial characterisation of silane films of a non-organofunctional silane, 1,2-bis(triethoxysilyl)ethane (BTSE), and an organofunctional silane, γ-mercaptopropyltrimethoxysilane (γ-MPS), deposited on Al, Zn and Al-43.4Zn-1.6Si (AlZn) alloy coated steel. Furthermore, a tribological study of a vegetable oil coupled to an aluminium surface pre-treated with γ-MPS is presented and, finally, the tribological response of thin organic coatings exposed to a sliding contact as evaluated by surface analysis is discussed. The main analyses techniques used were time-of-flight secondary ion mass spectrometry (ToF-SIMS), Auger electron spectroscopy (AES) and x-ray photoelectron spectroscopy (XPS). The results presented in this thesis show that the combination of ToF-SIMS, AES and XPS analysis can be used in order to obtain useful and complementary information regarding the surface and interface characteristics of silane films and organic coatings deposited on metal substrates. The major result regarding the silane films is that the silane film composition/structure is not dependent of pH-value during deposition or type of metal substrate. The presence of Si-O-Me ion fragments in the ToF-SIMS spectra is a strong indication that a chemical interaction between the silane film and the metal substrate exists. Furthermore, it has been shown that it is possible to bond a vegetable oil to a thiol functionalised aluminium surface and to produce a coating thick enough to obtain desired friction and wear characteristics. Finally, the use of ToF-SIMS analysis makes it possible to distinguish between mechanical and tribochemical wear mechanisms.

WC/Co cemented carbide is a composite material for highly demanding wear applications. The unique combination of hardness (from the WC-phase) and toughness (from the binder Co) gives a material especially suitable for rock drilling. This thesis, investigates the deterioration and wear of these cemented carbide buttons and the correlation to different rock types. To better understand the nature of the wear of the cemented carbide buttons, the counter surface –the rock- has also been studied. A range of important rock types has been investigated with respect to hardness distribution and scratch response in a micro scale and friction properties when slid against cemented carbides. The cemented carbide may deteriorate due to a number of mechanisms. The effect of fatigue in the structure was studied in TEM and particle erosion response was used to probe the corresponding mechanical degradation. Further, homing cross sectioning has been developed and used as a new technique to investigate the presence of weak zones in the surface layer of a drill button. It was found that rock penetration into this layer is a very common mechanism, with profound implications for the nature of the wear. High resolution scanning electron microscopy has been extensively used to map the deterioration and wear of numerous drill buttons, worn against different rock types in different kinds of drilling applications. Finally, the collected data on the surface damage, the reptile skin formation, the rock intrusion and the properties of the rock are assembled into a new view of the deterioration and wear of cemented carbide in rock drilling.

For a long time spectrophotometry has been a powerful method of determining optical material properties. Since the technique measures the parameters of interest, reflectance and transmittance, it is in general easy to use and interpret. Certain materials, such as miniature structures or scattering materials, must be given a more careful analysis to avoid incorrect interpretation. General solutions to measurement challenges for thick scattering samples and anisotropically scattering samples are presented. Thorough knowledge about the components of a spectrophotometer gives a solid base which is necessary when trying to design or modify an instrument for the characterisation of miniature components. Focusing optics and pinhole apertures are two methods investigated for studying samples on a millimeter scale. Focusing optics retain a high intensity but might cause internal reflection. Pinhole apertures are easy to build into a sample holder, but they will reduce light intensity which can give problems with signal to noise ratio. Using a microscope as a focusing lens system permits the measurement of samples of a size down to the order of ten micrometers. However, absolute measurements are difficult due to the strong focusing properties of the microscope. Translucent sheets are of interest for daylighting applications, a growing field in today's energy-conscious society. If sunlight is to be used for indoor illumination it is preferable to make it diffuse. By using Transparent Refractive Index Matched Micro (TRIMM) particles in a transparent polymer sheet, it is possible to obtain high transmittance in combination with tailorability of the scattering profile. Such sheets have been characterised experimentally, as well as by Monte Carlo raytracing simulations. The good agreement between simulation and experiment shows that this type of simulation can be used in the materials design process. A more theoretical study of patterns in multiple Mie scattering has been carried out using the Monte Carlo program developed for characterisation of the TRIMM particle sheets.

Recent developments in thin film synthesis of diamond have facilitated a host of new technical applications. These are motivated by the many attractive properties of diamond, for example high hardness, chemical inertness, transparency and heat conductivity. Unfortunately, these properties also make it difficult to fashion complex geometries. Other problems are the severely limited choice of suitable substrate materials and large surface roughness. To reduce these complications, a technology denoted replication and bodybuilding has been developed. The basic principle is to grow the diamond film onto a mold and then build a mechanical support on top of the diamond film. Then the mold is removed. Thereby, a diamond surface with the desired 3D geometry and the same surface roughness as the mold is created. Three potential applications for devices built using the replication and bodybuilding concept have been explored. Grinding tools for hard materials have proved superior to conventional technology in rate of removal as well as in resulting surface finish. Diamond surfaces have also been crafted into ultra-durable dies for injection molding of hard particle reinforced polymers. Initial testing of an abrasive diamond device, intended to make CMP processes more economical and easier to control has successfully been carried out. Diamond and diamond-like carbon is well-known for being “low-friction materials”, but are here demonstrated to actually be “high-friction materials” with the ability to disguise themselves in certain environments, most notably with the aid of water molecules. The mechanisms involved in these variations have been investigated. Using NEXAFS it is shown that high friction sliding is accompanied by changes in the material structure. These changes are induced by surface roughness as well as by strong adhesive forces. Highly hydrogenated carbon coatings, on the other hand, affording super-low friction coefficients (<0.01) under certain circumstances, will suffer an increase in friction in the presence of water.

Electro-acoustic devices such as surface acoustic wave (SAW) and bulk acoustic wave (BAW) devices have been in commercial use for over 60 years and can be found in applications ranging from specialised scientific and military equipment to consumer products, such as mobile telephones, TV and radio receivers, etc. Today by far the largest market for electro-acoustic devices is the telecommunication industry which annually consumes approximately three billion acoustic wave filters for frequency control alone. The development of new materials and technologies for electro-acoustic devices has gained a substantial and growing interest from both academic and industrial research communities in recent years due to the enormous growth in the telecommunication industry and other forms of wireless data communication. One of the bigger issues has been to replace the single crystalline substrates with thin film piezoelectric materials deposited by reactive sputtering. This would not only reduce the manufacturing costs but will also enable high frequency of operation and a wider choice of substrate materials. However, in order to obtain the material properties required for the intended application a detailed theoretical description of the reactive sputtering process is necessary since the texture and other functional properties of the piezoelectric material are extremely sensitive to the process parameters in addition to the structure of the underlying material. This thesis studies the reactive sputtering process and its application for the fabrication of thin film electro-acoustic devices. The aim has been to gain a further insight into the process and make use of this knowledge to improve the fabrication of electro-acoustic devices. In this work modelling of the reactive sputtering process has been improved by studying certain fundamental aspects of the process and in particular the dynamics of the processes taking place during sputtering both at the target and the substrate surfaces. Consequently, highly textured thin piezoelectric aluminium nitride films have been synthesized and thin film bulk acoustic resonators (FBAR) operating in the GHz range have been fabricated and studied.

A microwave reflection method has been used to measure the spin excitations corresponding to the translational mode of magnetic vortices in samples containing either one or two vortices. Experimental findings are complemented by micromagnetic simulations. One-vortex systems are investigated in micron-sized circular and elliptical cylinders. For ellipses, the resonance frequency can effectively be tuned by applying static magnetic fields and the field dependence of the frequency is significant for fields applied along the short axes but negligible when applied along the long axes of the ellipses. This is contrary to the circular case, where virtually no field dependence was found. This can be understood by considering the shape of the vortex potential well. Further, it is found that the resonance frequency is independent on the direction of the excitation field for the one-vortex systems. Ellipses containing two interacting vortices are also investigated. It is shown that the relative vortex core polarizations dominate the vortex translational mode and cause, in the case of opposite polarizations, a dependence on the excitation field direction. For parallel core polarizations, no dependence on the excitation field direction is found. The dependence of the resonance frequencies on applied static fields along the long and short axes are also experimentally mapped out and compared with micromagnetic simulations, where the possible eigenmodes are determined. Another section of the thesis introduces the dawning of a device based on patterned magnetic elliptical elements for the manipulation and movement of magnetic particles on a surface. The controlled movement and separation of individual particles are successfully demonstrated. Contributions to micromagnetic standard problems and simulations on magnetization switching in nanoscale particles have also been performed. The standard problems highlight some important aspects of choosing the discretization cell sizes and the finite temperature simulations show that thermal fluctuations can alter the magnetization reversal paths.

The effect of compositional modulation on structural and magnetic properties of magnetic heterostructures was explored. The systems under focus were ferromagnetic superlattices Fe81Ni19/Co, metal-insulator multilayers Al2O3/Ni81Fe19, nanoparticles and artificial multilayered pillars. The heterostuctures were grown by magnetron sputtering in a state-of-the-art ultra-high vacuum system. The structural characterization was done by X-ray diffraction and reflectivity, as well as by transmission electron microscopy. Magneto-optical Kerr effect, SQUID and XMCD magnetometry and magnetic force microscopy were used for magnetic characterization. The bilayer thickness, ratio of the constituents and the interface quality influence the magnetic properties (magnetic moments and anisotropy) of metallic heterostructures. In particular, magnetic moments in bcc Fe81Ni19/Co superlattices were found to scale with the interface density thus, implying different magnetic moments at the interfaces as compared to the interior part of the layers. The easy direction of magnetization can be rotated from in-plane to out-of-plane, by increasing the bilayer thicknesses, keeping other parameters unchanged. Consequently, the anisotropy strength is strongly dependent on the repeat distance. Stripe domains appear in the films that possess an out-of-plane magnetization. The average domain period was found to be dependent on the applied in-plane magnetic field and on the total thickness of the films. The structural and magnetic properties of Al2O3/Ni81Fe19 multilayers depend strongly on the individual layers thicknesses. By increasing the amount of the magnetic deposits one can change the obtained film structure, from superparamagnetic nanoparticles to ferromagnetic multilayers. By increasing the oxide layer thickness the magnetic behavior of the nanoparticles can be altered from ferromagnetic, via spin glass like, to a superparamagnetic character.

The complexity of electronic systems in vehicles is rapidly increasing, and as a consequence, the long-term reliability of automotive connectors has become an important issue. The aims of this thesis have been: 1. to characterize the friction, wear and electrical properties of tin coatings, 2. to achieve an improved fundamental understanding of the deterioration processes caused by wear and fretting corrosion, 3. to propose improvements of tin coatings systems for electrical connectors. The required insertion force has a significant impact on the design and the cost of a connector. A reduced insertion force can be achieved by reduced contact load and/or reduced tin coating thickness, but this will increase the risk of fretting corrosion. Wear during the insertion stroke is essential in order to wipe off the non-conductive oxide layer. However, a thin tin layer may become worn off after only a few insertion strokes. The rider will then partly slide on the hard intermetallic compound formed between the substrate and the residual tin. Due to the restricted wear when sliding on the intermetallic compound more oxide will be formed during sliding than is removed and consequently the electrical contact resistance will increase. Two semi-empirical models are proposed, the first describing the contact resistance when the rider plows the free tin layer, and the second describing the contact resistance increase due to oxidation when the rider slides on the intermetallic compound. Two novel methods to improve the performance of pre-tinned material were evaluated. The first involves the use of a lubricant in combination with a textured surface, to improve the supply of lubricant into the contact spot. The second involves the addition of small amounts of a preferential oxidation additive to the tin. This increases the possibility of achieving a cold-welded contact spot, which results in an ultimately stable connection.

It is well known that thin coatings can provide increased lifetime and reduced energy consumption for tools and components. During use, e.g. in sliding contact, mechanical and chemical reactions often lead to the formation of new surface layers, tribofilms, possessing different properties compared to the original surface, hence affecting the overall performance. In this work, analytical electron microscopy was applied to investigate the structure and composition of tribofilms. Concerning coatings, deposition parameter dependencies, stability and tribology were investigated. The carbon content of hydrogen-free TiCx coatings was shown to significantly influence the morphology. Low carbon content resulted in columnar grains with a strong texture while high carbon content led to the formation of randomly ordered TiCx crystals. The application of positive bias to the substrate as opposed to the normally used negative bias gave a fibrous structure of sputtered TiB2 and low residual stress with maintained hardness. Further, oxidation stability was examined on a (Ta,Al)C:C coating where oxidation led to partial oxidation and formation of AlTaO4 with an 8 nm interface. A focused ion beam instrument was used to extract samples from certain areas of worn specimens. Tribological contact was observed to result in phase changes and intermixing of materials present in the contact. Sliding contact involving a Co-alloy led to a phase change from fcc to hcp. A 30 nm Co-rich tribofilm was observed with basal planes parallel to the surface. Fully formulated oil was found to inflict considerable wear to a metal doped carbon film through chemical reaction with the metal dopant. WC/Co cemented carbide used for rock drilling exhibited intermixing of rock and Co binder phase after field tests. Chemical vapour deposited diamond worn in nitrogen and argon showed formation of wear debris with amorphous structure containing nitrogen and graphitic like structure, respectively.