Bilayer orthogonal ferromagnetism in CrTe₂-based van der Waals system.

Abstract

Systems with pronounced spin anisotropy are pivotal in advancing magnetization switching and spin-wave generation mechanisms that are fundamental to spintronic technologies. Quasi-van der Waals ferromagnets like Cr_1+δTe₂ represent seminal materials in this field, renowned for their delicate balance between frustrated layered geometries and magnetism. Despite extensive investigation, the nature of their magnetic ground state and the mechanism of spin reorientation under external fields and varying temperatures remain contested. Here, we exploit complementary techniques to reveal a previously overlooked magnetic phase in Cr_1+δTe₂ (δ = 0.25 - 0.50), which we term orthogonal-ferromagnetism. This phase consists of atomically sharp single layers of in-plane and out-of-plane maximally canted ferromagnetic blocks, which differs from the stacking of multiple heterostructural elements required for crossed magnetism. Contrary to earlier reports of gradual spin reorientation in CrTe₂-based systems, we present evidence for abrupt spin-flop-like transitions. This discovery further highlights Cr_1+δTe₂ compounds as promising candidates for spintronic and orbitronic applications, opening new pathways for device engineering.