The Nanoshell nanoparticle source from Mantis Deposition is designed to aid in the production of core-shell nanoclusters. The core-shell structures play crucial role in the engineering of material properties on the nano scale.
The ability to construct a shell of one element or compound around a core of another opens up a range of possibilities not accessible to simpler structures, providing an additional degree of freedom in the design of new functional materials.
The Nanoshell coater takes nanoparticles formed in the NanoGen50 and focusses them into a well-defined beam. The focussing electrostatics lenses slow the beam down to increase its dwell time in the reaction area. The reaction area features a linear magnetron, which creates a vapour of sputtered material that condenses on the nanoparticle to form a shell.
This construction brings a number of benefits which separate the Nanoshell coater from other alternative methods:
The UHV environment ensures that contaminants are kept to a minimum. Complications relating to the presence of impurities in the core-shell structure can be avoided.
The relative size and composition of the core and the shell can be precisely controlled by a combination of parameters such as magnetron power, gas flow rate, presence of reactive gas, particle velocity and electrode potential.
A wide range of structures and sizes can be produced quickly and efficiently. The dwell time of nanoclusters in the shell coating region can be varied to control shell thickness.
Most other techniques rely on temperature or chemical reaction kinetics to produce the final structure. Therefore, the structure is typically limited to what is achievable at equillibrium. In Nanoshell, there are additional degrees of freedom available. For example, if nanoparticle temperature is carefully managed, it may be possible to form core-shell structures from elements which are usually miscible.
Increased particle sizes
The shell structure need not be formed from a different material. It is possible to add more material to a nanoparticle to increase its diameter.