Direct Visualization of Canted Magnetization and Topological Charges in Self-Intercalated van der Waals Magnet Cr _1+δ Te ₂ with Hidden Structural Phases

Intercalated van der Waals (vdW) magnets have attracted growing interest owing to their rich and highly tunable magnetic properties and their promise for ultracompact spintronic applications. A remarkable example is self-intercalated chromium tellurides (Cr 1+δ Te 2 ), in which spatially ordered chromium atoms occupy the vdW gaps, yielding a variety of known compounds (e.g., Cr 1.25 Te 2, Cr 1.33 Te 2, and Cr 1.5 Te 2 ) that host distinct and intriguing magnetic states. In this work, we uncover the existence of hidden, ordered self-intercalated phases that form spontaneously along with a twisted Cr 1.5 Te 2 phase in chromium telluride nanoflakes grown by chemical vapor deposition. Using wide-field and scanning diamond nitrogen-vacancy center (NV) magnetometry, we unveil intricate magnetic structures in the chromium telluride flakes at the nanoscale and above room temperature. In a small nanoflake, the magnetization prefers an in-plane orientation in its interior with strong anisotropy but is tilted out of plane at the edges. In a large nanoflake, we observe complex magnetic profiles indicating the possible formation of nontrivial localized topological structures. Our work demonstrates the versatility of self-intercalation beyond known phases and the rich magnetic properties in a model vdW magnet, highlighting its great potential for room-temperature spintronic applications.