Molecular magnetism has been developed towards the end of the 20th century, with the growing interest in molecular materials as low cost materials whose properties can be tuned by chemical techniques. Nowadays, the continuous trend towards miniaturizing electronic devices makes the device potentials of single (non magnetic and magnetic) molecules of great interest. Also for fundamental research, magnetic molecules are very appealing because in these systems quantum properties coexist with classical ones.
Between magnetic molecules, compounds of the single molecular magnets (SMM) class are particularly attractive. The first reported and mostly investigated example of SMM is Mn12ac, which is shown in Fig.1a.
interested in the magnetic and electronic
properties of magnetic molecules and SMM adsorbed in the sub-monolayer
surfaces of ultra-thin magnetic and non-magnetic films. We are
the electronic transport of ultra-thin films is influenced by the
the molecular magnetic moments adsorbed on their surfaces.
For transport measurements, we use insulating substrates with pre-fabricated leads which define the electrode geometries (see Fig.2). We evaporate the thin films using shadow masks and measure the conductivity of the films in situ with the four probe method.
For magnetization and magneto-transport measurements we use a SQUID magnetometer (able to apply magnetic fields up to 7T) which is able to detect magnetic moments as low as 10-9 emu.
Our research is now focused on the development of techniques for adsorption of SMM on surfaces, growth and characterization of ultra-thin films whose transport properties change drastically due to the presence of few magnetic moments on their surfaces.
This project is part of an NSF NIRT grant called "Molecular Spin-Active Nanoelectronics". Member of this grant is an interdisciplinary team that includes members from the Physics and Chemistry of UC Berkeley and Hardvard, as well as the microscopy group at the IBM Almaden Research Center.