Dielectric and magnetic relaxations of the quantum nanomagnet Mn12-Acetate

Abstract The temperature dependent dielectric and magnetic relaxations in the quantum nanomagnet Mn12-Acetate and its partially and fully deuterated analogs have been studied. One magnetic mode and four dielectric modes have been identified in the temperature interval from 300 K to 2.8 K and in the frequency range from 20 Hz to 1 MHz. The relaxation times of all modes follow an Arrhenius law. Comparison of the magnetic susceptibility mode to the NMR data shows that the magnetic susceptibility mode can be related to the magnetization reorientation fluctuations, while three slowest dielectric modes can be attributed to the motion of H2O and the forth mode to that of the CH3 groups.