Addition of a radical to the bridging tetrazine ligand of a Dy₂ complex dramatically alters the magnetic properties. The radical complex undergoes magnetic relaxation via a thermal relaxation pathway, whereas the neutral compound relaxes via quantum tunneling of the magnetization.

The first octadecanuclear {Cu₆Ln₁₂} clusters with a ‘windmill’-like topology have been prepared from a ‘ligand blend’ comprising a pyridyl dioxime chelate and azides.

Optical Physical Unclonable Functions (PUFs) are well established as the most powerful anticounterfeiting tool. Despite the merits of optical PUFs, widespread use is hindered by existing implementations that are complicated and expensive. On top, the overwhelming majority of optical PUFs refer to extrinsic implementations. Here we overcome these limitations to demonstrate for the first time strong intrinsic optical PUFs with exceptional security characteristics. In doing so, we use Computer-Generated Holograms (CGHs) as optical, intrinsic, and image-based PUFs. The required randomness is offered by the non-deterministic fabrication process achieved with industrial friendly, nanosecond pulsed fiber lasers. Adding to simplicity and low cost, the digital fingerprint is derived by a setup which is designed to be adjustable in a production line. In addition, we propose a novel signature encoding and authentication mechanism that exploits manifold learning techniques to efficiently differentiate data reconstruction-related variation from counterfeit attacks. The proposed method is applied experimentally on silver plates. The robustness of the fabricated intrinsic optical PUFs is evaluated over time. The results have shown exceptional values for robustness and a probability of cloning up to $$10^{-14}$$10 - 14 , which exceeds the standard acceptance rate in security applications.