Enhanced alignment of Mn12-acetate micro-crystals

A dilute Mn12-acetate suspension composed of microscopic single crystals and single molecules in isopropanol was used for magnetic studies of Mn12-acetate single molecule magnets. We observed magnetic properties of the frozen Mn12-acetate suspension similar to large single crystals, specifically several sharp steps in the low-temperature hysteresis loop, indicating significantly enhanced alignment as compared to prior studies of micro-crystals. The greater the external magnetic field during alignment, the sharper the steps were in the low-temperature hysteresis loops, indicating that this method can be used for continuous control of alignment. A magnetic field of ∼0.5 T was sufficient to align the micro-crystals in the organic solvent to a degree previously observed only in much larger single crystals.