Current-induced domain wall motion (CIDWM) is one of the most important spintronics research fields because it can be applied to new magnetic devices such as a racetrack memory, spin-transfer majority gate, and so on. They constitute an attractive technology thanks to their non-volatility and fast operation. From material engineering, our group has focused on Mn4N and Mn4−xNixN films as new candidates for CIDWM. We recorded the DW velocity of 900 m/s in Mn4N, and 3000 m/s in Mn4−xNixN at the vicinity of its angular momentum compensation (at x ∼ 0.2) at room temperature. These are the fastest records among CIDWM by pure spin-transfer torques (STTs). In this context, we investigated their magnetic and magneto-transport properties to understand especially the interaction between conduction and localized electrons and attempted to perform SOTs-driven CIDWM for more efficient operation.Chapter 1 focuses on the theory of magnetism, especially ferrimagnets, and the torques which induce CIDWM. We also showed the advantage of the compensation in ferrimagnets for CIDWM and benchmark CIDWM in the literature.In chapter 2, we present an overview of Mn4N and Mn4N-based compounds. First, we explain the fundamental properties of Mn4N and concluded that they are beneficial for CIDWM. Then, we present our experiments of CIDWM in Mn4N and Mn4−xNixN, in which we evidence the link between the observed fast DW velocity and the angular momentum compensation of Mn4−xNixN. We also introduce previous reports and our own studies on Mn4N-based compounds and explain the compensation in other nitrides such as Mn4−xCoxN.In chapter 3, we attempt the growth of Mn4N epitaxial films on various substrates to investigate the origin of PMA in Mn4N. Our previous study reached the assumption that its PMA derives from the in-plane tensile strain of Mn4N, however, this correlation was not been proven yet. We succeeded in the modulation of the tensile strain by the thickness and the lattice mismatch between Mn4N and the growth substrate. In the end, we found a clear correlation between PMA and the magnitude of the ratio of lattice constants of Mn4N (c/a). We thereby concluded that PMA derives from the spontaneous in-plane tensile strain of Mn4N films and that it is possible to control its PMA by applying external stress to films.In chapter 4, we investigate the magneto-transport properties of Mn4−xNixN from anisotropic magnetoresistance (AMR) and anomalous Hall effect (AHE) measurements. From AMR, we found a change of the d electrons state by temperature, which became less effective with Ni insertion. Our ab-initio calculation of PDOSs of Mn4−xNixN proved that it derives from a drastic shift in the Fermi level and the change in the PDOS of Mn even by small Ni composition. Also, we analyzed the scaling of AHE and discovered that large intrinsic deflection contributes to the AHE in Mn4N at low temperatures while extrinsic scatterings become dominant at high temperatures or in Mn4−xNixN.In chapter 5, we aim at the growth of the heterostructure of heavy metal (HM) (Pt or W) and Mn4N to attempt SOTs-driven CIDWM from the spin Hall effect. We observed large and stable magnetic domains in these samples, however, we also found that the magnetization reversals are affected by DW pinnings, which may come from the interfacial condition such as alloying and damaging by the sputtering process of the HM layer. We process them into multiwires for CIDWM investigation and achieved DW velocity of 420 m/s. However, we could not find a clear effect of SOTs on CIDWM. We propose that measurements with an in-plane field should be performed to form chiral Néel DWs, a prerequisite for the use of SOTs by SHE.To conclude, the modulation of PMA by the strain and of the magneto-transport properties by dopants will broaden the possibility of Mn4N. The use of SOTs for Mn4N will be attempted with the assistance of the in-plane field and the optimization of the heterostructure.