As computing demands increase exponentially, so too has the desire for new computing technologies that operate faster and with greater efficiency. Ferromagnetic materials were initially seen as ideal candidates for use in memory and logic devices, and this field of study was termed “spintronics”. Subsequently many issues with using ferromagnets for this purpose have been discovered. They have high energy requirements for write operations, are sensitive to magnetic fields, and they produce stray fields which limit how densely elements may be packed together. Because of these challenges, interest has turned to antiferromagnetic materials (AFMs) which do not possess sensitivity to magnetic field, may be packed densely together, have multi-level stability, and have theoretical switching speeds 100 times faster than ferromagnets. These advantageous features bring the added complication that characterising AFMs, in particular thin films suitable for use in ICT, is notoriously challenging due to the vanishing magnetisation.
In this thesis, we grow and investigate thin films of the antiperovskite family Mn3AN, where A = Ni, Sn. These materials possess particular non-collinear antiferromagnetic structures that lead to anomalous physical properties not normally expected in AFMs. We first look at the anomalous Hall effect (AHE), and show how strain applied using a piezoelectric substrate may be used to manipulate the intrinsic contributions to the AHE in Mn3NiN. We then use a scanning laser to induce a local thermal gradient in a patterned device, and by measuring the anomalous Nernst effect we reveal the underlying antiferromagnetic macrodomain distribution. Finally, we
measure the MOKE spectra of a Mn3NiN sample for selected temperatures cooling through the Néel temperature, TN, and from comparisons with theory confirm the presence of a ferrimagnetic phase above TN. This phase shares the same magnetic space group as the non-collinear phase, and shows promise for spintronic applications at room temperature.