Síntesis, caracterización y estudio en superficie de nanoimanes moleculares.

Abstract

Single-molecule magnets (SMM) have a large-spin ground state with appreciable magnetic anisotropy, resulting in an energy barrier for the spin reversal. As a consequence, the observation of interesting magnetic properties occurs, such as out-of-phase ac magnetic susceptibility signals and stepwise magnetization hysteresis loops. In addition to resonant magnetization tunnelling, during the last few years several other interesting phenomena have also been reported. The origin of the slow magnetization relaxation rates as well as of other phenomena are due to individual molecules rather than to long-range ordering, as confirmed by magnetization relaxation and heat capacity studies. Therefore, SMM represent nanoscale molecular magnets of a sharply defined size with potential use in quantum computing applications and towards the realization of the ultimate high-density information storage devices. However, if a truly molecular computational device based on SMM is to be achieved, the development of new spectroscopic techniques to detect them rapidly, taking advantage of magneto-optical properties, as well as new systematic studies to address them properly on surfaces, are highly required. On the basis of this, patterning with Mn12 aggregates can be attained on surfaces by applying soft lithography techniques, thereby controlling their size, distance and geometry control. Surface characterization of Mn12 patterns have been studied by Atomic Force Microscopy (AFM) and Magnetic Force Microscopy (MFM) imaging. For instance, the surface of polymer thin films results particularly interesting because of the advantageous properties of polymer matrices, such as flexibility, transparency and low density, which make these magnetic materials potentially useful for magneto-optical applications.

Date of Award	4 Nov 2005
Original language	Undefined/Unknown
Supervisor	José Luis Bourdelande Fernández (Director) & Daniel Ruiz Molina (Director)