Enhanced magnetization in proton irradiated Mn3Si2Te6 van der Waals crystals

Abstract

van der Waals (vdW) engineering of magnetism is a topic of increasing research interest in the community at present. We study the magnetic properties of quasi-two-dimensional layered vdW Mn3Si2Te6 (MST) crystals upon proton irradiation as a function of fluences of 1 × 1015, 5 × 1015, 1 × 1016, and 1 × 1018 H+/cm2. We find that the magnetization is significantly enhanced by 53 % and 37 % in the ferrimagnetic phase (at 50 K) when the MST crystal was irradiated with the proton fluence of 5 × 1015, both in ab and c planes, respectively. The ferrimagnetic ordering temperature and magnetic anisotropy are retained even after proton irradiation. From the fluence dependence of magnetization, electron paramagnetic resonance spectral parameters (g-value and signal width), and Raman data, we show that the magnetic exchange interactions (Mn–Te–Mn) are significantly modified at this fluence. This work shows that it is possible to employ proton irradiation in tuning the magnetic properties of vdW crystals and provide many opportunities to design desired magnetic phases.