Room-temperature weak collinear ferrimagnet with symmetry-driven large intrinsic magneto-optic signatures

Here we present a magnetic thin film with a weak ferrimagnetic (FIM) phase above the Neel temperature (TN = 240 K) and a noncollinear antiferromagnetic (AFM) phase below, exhibiting a small net magnetization due to strain-associated canting of the magnetic moments. A long-range ordered FIM phase has been predicted in related materials, but without symmetry analysis. We now perform this analysis and use it to calculate the magneto-optical Kerr effect (MOKE) spectra in the AFM and FIM phases. From the good agreement between the form of the measured and predicted MOKE spectra, we propose the AFM and FIM phases share the magnetic space group C2'/m' and that the symmetry-driven magneto-optic and magneto-transport properties are maximized at room temperature in the FIM phase due to the nonzero intrinsic Berry phase contribution present in these materials. A room temperature FIM with large optical and transport signatures, as well as sensitivity to lattice strain and magnetic field, has useful prospects for high-speed spintronic applications.

Automated summary

A magnetic thin film with weak ferrimagnetic and noncollinear antiferromagnetic phases is studied, showing a small net magnetization due to strain-associated canting. Symmetry analysis and calculation of magneto-optical Kerr effect (MOKE) spectra suggest that both phases share the same magnetic space group. Additionally, the material exhibits good magneto-optic and magneto-transport properties at room temperature, making it a promising candidate for spintronic applications.