Preparation, Characterization And Structure Transformation Analysis Of Single Molecular Magnets

Since J. R. Friedman et al. first observed macroscopic quantum tunneling (MQT) on Mn₁₂-Ac in 1996, the research on single molecular magnets (SMM) such as Mn₁₂-Ac has received much attention. It has been hotspot in many researching areas, such as condensed matter physics, magnetism, materials science and so on.Preparing the high quality single crystal is one of the most important works for the research on SMM. This paper focuses on how to prepare Mn₁₂-Ac crystal, especially on how to prepare millimeter size Mn₁₂-Ac crystal. In this research, many experiments have been done and many factors have been considered in the experiments. And it's found that the suitable temperature, clean room, dry container and even stir are crucial for controlling the crystal nucleation. Also, the effects of temperature programming on preparing the millimeter size Mn₁₂-Ac crystal were studied. Experiments show that temperature programming is important for growing the good and big Mn₁₂-Ac crystal and controlling the form of the crystal. By kinds of characterizations, it's proved that the single crystals we prepared have few structure defects.In this paper, the transformation of the Mn₁₂-Ac crystal structure has been analyzed. It's found that only if the Mn₁₂-Ac has good crystal structure and...