Research

PRONANO: Electronic and Magnetic Properties of Chemically-Grown Nanoparticles

Research project selected under the 2011 call for proposals

Principal Investigator :

Benjamin Lassagne ()
LPCNO (Groupe Nanostructure et Chimie Organo-métallique et Groupe Nanomagnétisme)

Type of project : Collaborative Project

Partner team(s) :

LNCMI (Groupe Nano-objets et Nanostructures Semi-conductrices)

CEMES (GNS - Nanoscience)

Date (start/end) : 2012 - 2014

a) Nano-observer (CSI) multimode AFM inserted in a Jacomex glove box under Ar atmosphere. b) Ultra High Vacuum thin film deposition system from Plassys coupled with an M-Braun glove box under Ar atmosphere. c) and d) Fe nano-sphere deposited by dielectrophoresis on top of Au inter-fingered electrodes and capped with a Al 2 O 3 layer. e) AFM image of a carbon nanotube connected to two Cr/Au electrodes. The nanotube diameter is 1nm. Insert : Scheme of a carbon nanotube mechanical resonator allowing to make magnetometry. A single NO is grafted onto the nanotube. f) AFM image of an Au nano-wire bundle connected to two Cr/Au electrodes. The bundle height is 20nm.

Abstract

Our project is focused on the study of the electronic and magnetic properties of individual or auto-organized metallic nano-objects (NO) synthesized in a control way by organometallic chemistry. Those NO (Co nano-rods, Fe nano-cube and nano-sphere, Pt stars, Au nanowire…) are synthesized by the “Nanostructure and Organometallic Chemistry” group of the LPCNO which has developed specific methods using chemical ligands to control the shape and the size of the NO.

The NO magnetic and electronic properties are studied by the “Nanomagnetism” (NM) group of the LPCNO and the “Nano-objects and Semi-conducting Nanostructures“ (NOSN) group of the LNCMI. More precisely, the NM group use two techniques to characterize and study the NO; the first technique is based on magneto transport measurement on auto-organized NO network and the second one is based on a new technique using carbon nanotube mechanical resonator to measure by torque magnetometry the magnetic hysteresis of a unique NO grafted on the nanotube. The NONS group is focused on the study under low temperature and high magnetic field of the electronic confinement and of the different regime of electronic conduction inside gold nano-wire.

All those studies require keeping the NO free from oxygen and water in order to conserve the NO shape and to avoid contamination and oxidation which will deteriorate drastically the intrinsic properties of the NO.

To achieve this goal we have developed a technological platform able to address, connect, manipulate, observe and characterize NO in an inert atmosphere without oxygen, and water. This technological platform is based on two coupled systems. The first system is a four hands glove box under Ar atmosphere coupled to an Ultra High Vacuum thin film deposition system from Plassys (see figure b)). Inside the glove box we have installed several deposition techniques like drop casting, dip coating, spin coating and dielectrophoresis. The UHV thin film deposition system is connected thanks to a transfer chamber. With this system we can depose metal layer to connect the NO (figure e) and f)) or oxide layer to protect the NO from oxidation (Al 2 O 3 capping layer on top of Fe nano spheres, figure d)). The second system is a multimode Atomic Force Microscope (AFM Nano-observer from CSI)) inserted in a specially designed two hands glove box (see figure a)). Thanks to the different modes available with the AFM it is possible to:

  • Locate , address and characterize the NO dimensions deposited on Si/SiO 2 thanks to the tapping mode (figure e) and f)). Then electronic properties measurements can be done under magnetic field and low temperature.
  • Study the magnetic properties of NO network deposited onto a substrate thanks to the magnetic mode imaging.
  • Perform local electronic properties measurement on individual NO thanks to the Resiscope mode developed by CSI.
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