Permanent magnet synchronous machines (PMSM are considered as viable options for automotive and traction applications. Rare earth magnets such as Neodymium Iron Boron (NdFeB is the most common choice in the PMSM for electric vehicles to achieve high power density machines. However, rare earth magnets are problematic from ethical and sustainability perspectives. From these perspectives, there are better magnet alternatives, such as ferrites. Ferrite magnets are well known for lower environmental impact, abundance and low cost. Due to a lower residual flux density of a ferrite magnet than that of a rare earth magnet, a larger amount of ferrite magnets are needed to achieve the same performance. This master thesis is aimed to compare a PMSM using NdFeB magnets with a PMSM using ferrite magnets in terms of different parameters such as torque production, power factor, drive cycle efficiency, losses mapping, cost, and environmental impact. The machines are designed based on the Volvo XC40 vehicle requirements. In order to compare both the machines, ferrite based machine with different types of rotor structures such as arc and spoke type configurations are designed in Ansys Maxwell and compared with the reference PMSM holding NdFeB magnet. The demagnetisation study was performed on the ferrite magnets at lower temperature in order to investigate the feasibility of the design. In order to reduce the risk of demagnetisation, a parametric analysis of the rotor structure has been conducted. Furthermore, the mechanical integrity was investigated at top speed. / Permanent magnet-synkronmaskiner (PMSM) betraktas som lönsamma alternativ för fordons och dragapplikationer. Sällsynta jordartsmagneter som Neodymiumbor (NdFeB) är det vanligaste valet i PMSM för elfordon att uppnå maskiner med hög effektdensitet. Sällsynta jordartsmagneter är emellertid problematiska ur etiska perspektiv och hållbarhetsperspektiv. Ur dessa perspektiv finns det bättre magnetalternativ, såsom ferriter. Ferrit är välkänt för lägre miljöpåverkan, överflöd och låga kostnader. På grund av låg restflödestäthet hos en ferritmagnet än en sällsynt jordartsmagnet behövs en större mängd ferritmagneter för att uppnå samma prestanda. Detta examensarbete syftar till att jämföra en PMSM med hjälp av NdFeB-magneter med en PMSM som använder ferritmagneter i termer av olika prestandaparametrar såsom vridmomentproduktion, effektfaktor, drivcykeleffektivitet, kartläggning av förluster, kostnad och miljöpåverkan. Maskinerna är designade baserat på Volvo XC40 fordons krav. För att jämföra båda maskinerna utformas ferritbaserad maskin med olika typer av rotorstruktur, såsom båg- och ekertypskonfiguration i Ansys Maxwell och jämförs med referensen PMSM som håller NdFeB-magneten. Demagnetiseringsstudien utfördes på ferritmagneterna vid lägre temperatur för att undersöka designens genomförbarhet. För att minska risken för demagnetisering har den parametriska analysen av rotorstrukturen genomförts. Dessutom undersöktes mekanisk integritet i toppfart.

Sr₃Ru₂O₇ is a quasi-two-dimensional metal and has a paramagnetic ground state that is heavily renormalised by electron-electron correlations and magnetic exchange interactions. Inextricably linked to this renormalisation is the metamagnetism of Sr₃Ru₂O₇ - a rapid rise in uniform magnetisation over a narrow range of applied magnetic field. Knowledge of the zero-field physics is essential to any description of the metamagnetism. Light may be shed on the enigmatic ground state of Sr₃Ru₂O₇ by doping the crystal lattice with foreign cations: this is the primary purpose of the original research referred to in this thesis, in which studies of some of the electronic properties of crystals of cation-doped Sr₃Ru₂O₇ are reported. Single crystals of Sr₃(Ru[subscript(1-x)]Ti[subscript(x)])₂O₇ and Sr₃(Ru[subscript(1-x)]Cr[subscript(x)])₂O₇ have been synthesised in an image furnace and some of the properties of these crystals have been measured. Evidence that indicates the emergence of a spin density wave as a function of Ti-doping in Sr₃(Ru[subscript(1-x)]Ti[subscript(x)])₂O₇ is presented. Time-dependent magnetic irreversibility has been observed in samples of Sr₃(Ru[subscript(1-x)]Cr[subscript(x)])₂O₇, thus hinting at the involvement of the RKKY mechanism in these materials. Regarding cation doping out of the conducting RuO₂ planes, samples of (Sr[subscript(1-y)]La[subscript(y)])₃Ru₂O₇ have been grown and investigated. Both the Sommerfeld coefficient and the Fermi liquid A coefficient of (Sr[subscript(1-y)]La[subscript(y)])₃Ru₂O₇ are found to decrease as a function of y (0 ≤ y ≤ 0.02); these observations point towards a reduction in the thermodynamic mass of the Landau quasiparticles. Results from magnetoresistance and magnetisation measurements indicate that the metamagnetism of the (Sr[subscript(1-y)]La[subscript(y)])₃Ru₂O₇ series probably cannot be explained by a rigid band-shift model. Also, some aspects of these data imply that the metamagnetism cannot be fully accounted for by a spin fluctuation extension to the Ginzburg-Landau theory of uniform magnetisation.