Fabrication and magnetic–electronic properties of van der Waals Cr4Te5 ferromagnetic films

Abstract

Exploiting two-dimensional van der Waals (2D vdW) room temperature ferromagnetic materials is always significant and valuable work. However, the actual number of satisfactory materials with intrinsic ferromagnetism is very limited. Here, the 2D layered Cr₄Te₅ epitaxial films prepared by a pulsed laser deposition technique were confirmed to hold a ferromagnetic ordering state up to 300 K. We find that the Cr₄Te₅ films can easily achieve epitaxial growth along a single orientation of the hexagonal Al₂O₃(0001) substrate. However, as for the cubic SrTiO₃(001) and multiphase structure mica substrates, the Cr₄Te₅ films only show uniaxial growth instead of epitaxial growth. Based on the investigation of electronic transport in the metallic regime, it is revealed that the interaction of electron–magnon scattering only exists in the lower temperature region. Our work renders 2D vdW Cr₄Te₅ crystals a very promising material for developing practical spintronic nanodevices.