It is demonstrated by means of exact numerical methods that the ground state of nine-membered frustrated homometallic chromium-based molecular rings with a single bond defect can be unambiguously determined by the in-field local magnetization profiles, which exhibit characteristic patterns. The strength of the coupling corresponding to the defect can be determined by both total and local magnetization measurements on single crystals with the field perpendicular to the ring. This approach is illustrated with a recently synthesized chromium ring Cr${}_9$Cl${}_2$, which is experimentally characterized by low-temperature magnetic measurements and analyzed by means of the microscopic quantum model. The strength of the coupling corresponding to the defect is estimated by fitting the magnetic susceptibility of a powder sample and independently confirmed from the experimental intersection point of total magnetization profiles preserving the typical values of the remaining parameters, which are well established for known chromium rings.

• Received 14 December 2012

DOI:https://doi.org/10.1103/PhysRevB.87.184430