Tunable crossover between one- and three-dimensional magnetic dynamics in Co-II single-chain magnets organized by halogen bonding.

Low-temperature magnetometry, ac susceptibility, and calorimetry have been employed to study Co-based single-chain magnets (SCMs) organized through halogen bonding. Magnetic hysteresis and maxima in the dc and ac susceptibilities, respectively, confirm the SCM behavior of the system. Several characteristic magnetic relaxation regimes are observed at different temperatures, which can be associated with both intra-and interchain exchange interactions. Remarkably, tweaking the rate at which an external magnetic field is swept along the axis of the chains enables a controlled transition between the one-and three-dimensional dynamics. Experiments on an isostructural Co-based SCM system crystallized with different halogens do not show three-dimensional dynamics, illustrating the importance of halogen bonding on the control of interchain interactions.