Films of Mn 12-acetate deposited by low-energy laser ablation

Department of Chemistry, Texas A&M University, 77843-3012, College Station, TX, USA
Journal of Magnetism and Magnetic Materials (Impact Factor: 1.97). 12/2004; 284(1):215-219. DOI: 10.1016/j.jmmm.2004.06.057
Source: arXiv


Thin films of the molecular magnet Mn12-acetate, [Mn12O12(CH3COO)16(H2O)4]·2CH3COOH·4H2O, have been prepared using a laser ablation technique with a nitrogen laser at low laser energies of 0.8 and 2mJ. Chemical and magnetic characterizations show that the Mn12-acetate cores remain intact and the films show similar magnetic properties to those of the parent molecular starting material. In addition, the magnetic data exhibit a peak in the magnetization at 27K indicating the creation of an additional magnetic phase not noted in previous studies of crystalline phases.

Download full-text


Available from: Kim R Dunbar
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Magnetic hysteresis is considered adistinctive feature of bulk magnetic materials, where it arises from long-range ordering and irreversible motion of domain walls. However, many anisotropic high-spin molecules, referred to as Single-Molecule Magnets (SMMs), display ahysteresis loop at low temperature and have the potential of being used as molecular-scale units for information storage. This work reviews recent advances in the realization of new bulk materials and low-dimensional nanostructures based on SMMs. Particular reference will be made to mixed-valence Mn12 complexes, which comprise the most versatile and best-performing SMMs available to date. Nonetheless, the described criteria for structure tailoring as well as the guiding principles in material design are of general value and applicability. Examples are given of multifunctional materials of either inorganic or hybrid nature which combine in aunique fashion the magnetic properties of embedded SMMs with the conductive, optical and mechanical characteristics of apolymeric host. In the framework of the molecular approach to electronics, successful attempts to organize SMMs into bidimensional arrays on surfaces and to address them individually have been reported. Recent results in this area will be treated exemplarily, with emphasis on molecular design and surface functionalization. The construction of molecular-scale electronic devices embodying SMMs as active components is finally highlighted among the future developments of this lively research area, which straddles the interface between chemistry and physics.
    Full-text · Chapter · Mar 2006
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Thin films of the single molecule magnet [Mn12O12(CH3COO)16(H2O)4]·2CH3COOH·4H2O (Mn12-acetate) have been fabricated on a Si-substrate by the dip-and-dry method, a simple and robust technique. Atomic force microscopy and X-ray photoelectron spectroscopy characterizations reveal that homogeneous, thin films of a few molecular layers with smoothness at the molecular level are deposited. Significant changes in magnetic properties of Mn12-acetate exposed to the same solvent were observed in zero field-cooled and field-cooled magnetization, as well as AC-susceptibility measurements. The blocking temperature was found to increase to TB>10K at low magnetic fields, indicating an enhanced magnetic anisotropy.
    Full-text · Article · Jun 2006 · Journal of Magnetism and Magnetic Materials
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The process for the transfer of single-molecule magnets (SMM) from a macroscopic liquid solution into a nanoscale region of a SiO2 surface is presented. The method allows the fabrication of nanostructures consisting of Mn12bet on a silicon oxide template and the rest of the surface remains free of molecules. The silicon oxide dots are patterned and repeated the deposition process to show that template growth of SMMs did not depend on the geometry of the nanopatterns. The sensitivity of phase imaging to changes in energy dissipation process reveals that 16 particles are located around the dot edges and give rise to the formation of nanoscale rings of SMMs. X-ray photoelectron spectroscopy (XPS) provides the evidence for all the elements expected to be present in the grafted layers with binding energies in agreement with the expected bonding states.
    Full-text · Article · Jan 2007 · Advanced Materials
Show more