1. Specific heat of Nanocrystalline materials (Cu, Ru, Pd) are higher than their bulk counterparts. 2. The melting point of nanoparticles decreases dramatically as the particle size gets reduced 3. Thermal conductivity of Nanotubes are more than twice the conductivity of diamonds. 4. Thermal management: Carbon nano tubes (CNTs) have good thermal conductivity properties and…
· Magnetic moment: In nano-materials as large number of atoms are present in the surface, they have low co-ordination number and hence possess local magnetic moment with in themselves. · Due to large magnetic moment these nano-materials emhibits spontaneous magnetization at smaller sizes. · Super-paramagnetism is a form of magnetism, which appears in small ferromagnetic (or) ferrimagnetic nanoparticles….
· Change in colour: In semiconductors, bandgap changes with particle size; bandgap is the energy needed to promote an electron from the valence band to the conduction band. As particle size decreases, bandgaps increases and so wavelength of light emitted by the particles decreases. When the bandgaps lie in the visible spectrum, a change in bandgap…
There are three categories of materials based on their electrical properties: 1. Conductors, 2. Semiconductors and 3. Insulators. The energy separation between the valence band and the conduction band is called Eg (band gap). The ability to fill the conduction band with electrons and the energy of the band gap determine whether a material is…
· Nanoscience is the science of objects with typical sizes of 1-100 nm. If matter is divided into such small objects the mechanical, electric, optical, and magnetic properties can change. · Simply by finely dispersing ordinary bulk materials new properties can be created: inert materials become catalysts, insulators become conductors, or stable materials become combustible. · Most properties…
Multi-layered materials are heterostructures composed of many alternating layers that are generally stacked in a periodic manner. An artificially multi-layered material is shown schematically in figure below. · The combined thickness of two adjacent layers is called the bilayer repeat length or bilayer period. · The principal characteristic of multilayers is a composition modulation, that is, a…
Systems confined in one dimension, or quasi-2D systems, include discs or platelets, ultrathin films on a surface and multi-layered materials; the films themselves could be amorphous, single-crystalline or Nano crystalline. · A solvent that contains a molecular material that when applied to a surface, chemically aligns itself to form the strongest possible bond and appear as…
Systems confined in two dimensions, or quasi-1D systems, include nanowires, nano rods, nanofilaments and nanotubes: again these could either be amorphous, single-crystalline or polycrystalline (with nanometre-sized grains). The term ‘nano-ropes’ is often employed to describe bundles of nanowires or nanotubes. Types of Nanowires: · Metallic – Made from Nickel, Platinum or Gold · Semi-conducting – Comprises of…
A reduction in the spatial dimension or confinement of particles or quasi particles in a particular crystallographic direction within a structure generally leads to changes in physical properties of the system in that direction. Hence one classification of nanostructured materials and systems essentially depends on the number of dimensions which lie within the nanometre range….
Living systems are governed by molecular behaviour at the nanometre scale, where chemistry, physics, biology, and computer simulation all now converge. Implications for Physics: 1. Nanoscale materials mass is extremely small and gravitational forces become negligible. Instead electromagnetic forces are dominant in determining the behaviour of atoms and molecules. 2. Wave-Particle duality of matter: For…