Magnetic order in pulsed laser deposited films of van der Waals magnet (Fe,Ni)5GeTe2

We report the growth of highly textured thin films of (Fe,Ni)5GeTe2 two-dimensional ferromagnet on c-plane sapphire using pulsed laser deposition. Structural characterization via x-ray diffraction confirms preferential orientation along the (0001) direction, indicative of a high crystallographic texture. These films of van der Waals (vdW) type interplanar bonding exhibit robust ferromagnetism with a Curie temperature reaching ≈498 K. Electrical transport measurements reveal a clear anomalous Hall effect, with an anomalous Hall conductivity and Hall angle (%) of ≈20 Ω−1 cm−1 and ≈0.90, respectively. Furthermore, the magnetoresistance displays a pronounced dependence on film thickness, highlighting the tunability of spin-dependent transport in these vdW ferromagnetic thin films.