Observation of large interlayer magnetoresistance in CVD-grown PtSe2 single-crystal flakes

Abstract

As an emerging two-dimensional transition metal dichalcogenides (2D TMDCs), platinum diselenide (PtSe₂) has excellent properties such as narrow band gap and high carrier mobility, redering it an ideal candidate for spintronic devices. However, magnetic studies are still in their infancy for PtSe₂ single-crystal flakes grown by chemical vapour deposition (CVD). Herein, Observation of significant interlayer magnetoresistance (MR) in 2H-PtSe₂ single-crystal flakes grown by CVD is reported. By analyzing the magnetic transport properties at low temperatures, both PtSe₂ flakes with thicknesses of 23 nm and 141 nm exhibit butterfly-shaped hysteresis, confirming the ferromagnetic properties of 2H-PtSe₂. The 23 nm-PtSe₂ exhibits a higher maximum |MR| ratio of 2.62 % compared to 141 nm-PtSe₂ at 5 K, indicating that the magnetism has a more significant effect on the magnetoresistance of PtSe₂ with less layers. This phenomenon is similar to that observed in-plane, suggesting that the magnetic modulation of the intra-layer resistance in PtSe₂ is comparable to that of the inter-layer resistance. This study reveals the thickness magnetic properties of CVD-synthesised 2H-PtSe₂ and will provide richer theories and insights for future studies of PtSe₂-based spintronic devices.