Electrical switching of N'eel order in an antiferromagnetic (AF) material is desirable as a basis for memory applications. Unlike electrical switching of ferromagnetic order via spin-orbit torques, electrical switching of antiferromagnetic order remains poorly understood. We develop a sensitive, nanoscale scanning magnetic microscope using nitrogen-vacancy (NV) centers in diamond. The scanning NV-center microscope allows imaging of small magnetic fields from canted AFs and provides insights into their magnetic properties. First, we study the change of the magnetic order of a canted AF, α-Fe2O3, induced by an external magnetic field and electric current. Our results show that the orientation of an in-plane 1-Tesla magnetic field influences the sample's magnetic state even after relaxation in a low field. We find that our sample has an overall in-plane uniaxial anisotropy, in contrast to the 3-fold magneto-crystalline anisotropy suggested in previous work. Our observations from imaging current-induced magnetic order switching indicate that thermo-magnetoelastic effects alone are sufficient to induce magnetic switching in α-Fe2O3, and that spin-orbit torques may not be necessary. Second, we image the electric and magnetic textures of BiFeO3/TbScO3 (BFO/TSO) superlattices using piezoresponse force microscopy (PFM) and scanning NV-center microscopy. We observe spatially correlated electric and magnetic domains in a mixed-phase BFO/TSO superlattice, confirming that the polar and antipolar phases have different magnetization. To understand the magnetic properties of each phase, we image a pure-polar and a pure-antipolar sample, and find that contrary to our expectation, the antipolar sample has noticeable magnetic structures. We also study a TSO/BFO/TSO trilayer and observe a gradual change in magnetic textures consistent with a mixed-to-pure-phase transition close to the edge of the sample, which is potentially a result of local nonuniform strains.