The field of optics that deals with non – linear behavior of optical materials is known as non- linear optics. The material for which the optical properties depends on the intensity of light and behave non – linearly is called non linear optical (NLO) Materials. The physical properties of optical material depend on intensity of
Classification of Nonlinear Materials Read More »
Though nano-particles are very small, they are the important materials to built the future world. They have applications almost in all fields as follows Nanomaterials in Energy Production Generating steam from sunlight: The sunlight, concentrated on nanoparticles intended to use sunlight to generate steam for use in running power plants. Producing high efficiency light bulbs:
Applications of Nanomaterials – Pedagogy Zone Read More »
There are two general approaches to the synthesis of nanomaterials, they are (a) The top-down approach (b) The bottom-up approach (a) The top-down approach It is a approach in which smaller objects are made by carving or fabricating larger or bulk materials. It is like stone made into pieces from mountains (b) The bottom-up approach
Synthesis of Nanomaterials – Pedagogy Zone Read More »
Nanomaterials have the structural features in between of those of atoms or molecules and the bulk materials. The properties of nanomaterials change as their size approaches the nanoscale. Thermal properties : Nanomaterials have lower melting temperatures, when the particle size decreases below 100 nm. It is due to the fact that the surface energy level increases as
Properties of Nanoparticles – Pedagogy Zone Read More »
The term nano originated from the Greek nanos which means “dwarf”. It is one billionth of a meter. Therefore, whenever we think about nonoscience or nanomaterials very small objects come to the mind. A nanometre or nm is one thousand millionth of a metre, (ie), 1 nm=10−9 m=10−3 m=10 A. All materials are composed of grains, which in
Nanomaterials – Introduction Read More »
Ni-Ti alloy was developed in 1962 by Naval Ordnance Laboratory, White Oak, Maryland, USA and is commercialized under the name nitinol (nickel-titanium Naval Ordance Laboratory). Ni-Ti alloy shows shape memory effect when temperature or stress is applied. The Ni-Ti has proven to be the most flexible and beneficial in engineering applications. The Ni-Ti alloy have
Physical Properties of Ni-Ti Alloy Read More »
Shape memory effect It is the phenomenon in which the shape memory alloy apparently deforms at lower temperature and returns to its original shape (former shape) when heated at higher temperature. Let us consider a shape memory alloy for which the temperature is decreased. Due to decrease in temperature, phase transformation takes place from austenite
Characteristics of SMAs – Shape Memory Alloy Read More »
Definition : Shape memory alloys are special type of alloys that have the ability to return to a original defined shape when heated. Shape memory alloys are also called as smart materials (or) intelligent materials (or) active materials. The shape memory transformation was first observed by Chang and Read in 1932. Examples of SMA’s a)
Shape Memory Alloys (SMAs) – Pedagogy Zone Read More »
Since the atoms in the metallic glasses are disordered, they have some peculiar properties as follows. a) Structural properties Metallic glass have tetrahedral closely packed (TCP) structure rather than hexagonal closely packed (HCP) structure. They do not have any crystal defects such as grain boundaries, dislocations, etc. b) Mechanical (or) General properties The metallic glasses
Properties of Metallic Glasses – Pedagogy Zone Read More »
1. Calculate the intrinsic carrier concentration in germanium at 300 K. Given that me *=1.09 m0, mh *=0.31 m0 and Eg = 0.68 eV. Given T = 300 K, k=1.38×10-23 Jk-1, h=6.626×10-34 Js, m0 = 9.11×10-31 Kg, Eg = 0.68 eV = 0.68×1.6×10-19 J, me *=1.09 m0 = 9.929×10-31 Kg, mp* = 0.31 m0 =
Semiconducting Materials – Solved Problems Read More »