Spin selection rules on the quantum tunneling of magnetization in Mn3 molecule magnets with intermolecular exchange couplings

By means of low-temperature magnetic measurements, it is seen that, quantum spin selection rules also apply to the Mn 3 molecule magnets which have intermolecular exchange couplings. The absence of two splitting steps of the tunneling from |6〉 to |−5〉 indicates that the transitions are confined to the C 3 molecular symmetry. This is the first manifestation of quantum phase interference in the molecule magnets with intermolecular exchange couplings.