Magnetic Relaxation in a Single-Molecule Magnet Mn12-chlorobutylate

Magnetization measurements have been performed on the single-molecule magnet Mn12- chlorobutylate, a derivative compound of the well-known Mn12-acetate. A single crystal of Mn12- chlorobutylate has been characterized by measuring the magnetization as a function of the temperature and the magnetic eld. Below the blocking temperature, magnetization curves show hysteric behavior with distinct steps at well-dened elds, indicating the quantum tunneling of magnetization in this compound. Magnetic-relaxation measurements have also been performed at various temperatures, and the eective barrier height against magnetization reversal has been determined. As compared with Mn12-acetate, the relaxation rate is enhanced signicantly while the eective barrier height is almost unchanged. This observation is consistent with the existence of transverse anisotropy in this compound. KCI Citation Count: 7