Insulators conductors and semiconductors pdf
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- Difference Between Conductor, Semiconductor and Insulator
- Resistivity of conductors insulators and semiconductors pdf merge
- Conductors, insulators and semiconductors
- 15 Difference Between Conductor, Insulator And Semi-Conductor With Examples
The major difference between conductor, insulator and semiconductor is defined by the flow of charged particles under the influence of electric field. When any voltage is applied to the conductor, electric charged particles easily flow from valence band to conduction band. Thus conductor is a good conductor of electricity.
Difference Between Conductor, Semiconductor and Insulator
Levels of conductivity are the main difference between conductors, semiconductors and insulators. Conductors display high conductivity, which means they allow energy, such as electricity, heat or sound, to easily flow through them. Whereas semiconductors allow a moderate flow and insulators exhibit low conductivity. Whilst conductivity is the principal difference between conductors, semiconductors and insulators, there are a number of other differences between the three.
These differences may also need to be considered when thinking about their industrial and commercial uses. Here at Elmelin, we use specialise in providing industrial insulation material and solutions , using high-quality muscovite white mica and phlogopite green mica. Band theory is one of the main ways of explaining differences in conduction. Electrons orbit the positive nucleus of an individual atom within permitted levels of energy. In a lot of atoms, energy levels reorganise into two bands, namely the valence band and the conduction band.
The valence band is the lower level of electrons and the conduction band is the higher level of electrons. When conduction occurs electrons move and for this to happen there has to be spaces in the energy bands for the electrons to move into. A conductor facilitates the easy flow of an electron from one atom to another atom when the proper application of voltage.
This is because there are no band gaps between the valence and conduction bands. In some materials, there is an overlapping of the conductor and valence bands, which means electrons can move between the two overlapping bands. As there is space for elections to move into in the conduction band, valence band electron moves into the other band and conduction is allowed.
Silver is probably the best electrical conductor we encounter in everyday life. Other metals, such as gold, copper, steel, aluminium and brass also represent good conductors.
Solids are normally the best types of conductors, however, some liquids including liquid metals such as mercury are also good at permitting the transmission of energy through them.
Some materials are classed as superconductors. At extremely low temperatures these materials will conduct without resistance. The resistance of a semiconductor falls as its temperature rises. Elements like silicon Si , germanium Ge , selenium Se ; compounds like gallium arsenide GaAs and indium antimonide InSb are all examples of semiconductor elements. Silicon represents the most widely used semiconductor.
A rise in temperature increases the conductivity of a semiconductor because more electrons will have enough energy to move into the conduction band. Ordinarily, gases are poor conductors due to the space between atoms. However, in some circumstances — such as when it contains a large number of ions — gasses can be fair conductors and act as semiconductors.
An insulator prevents the flow of energy between two objects. For example, insulators may prevent the flow of electric, heat or sound. Thermal insulators, reduce the transfer of heat between two objects of differing temperatures. Thermal insulators do this by reflecting thermal energy. The insulative capacity of a material is the inverse of thermal conductivity k and therefore those materials with low thermal conductivity will have high insulating capability or resistance value.
A substance that does not conduct electricity is called a dielectric material. These substances can be polarised by an applied electric field so electric charges do not flow through them as they would through a conductor.
Therefore, the internal electrical field reduces the overall field within the dielectric. In insulators, there are larger gaps between the conduction and valence bands. The electrons cannot move into the conduction band and this means the material cannot conduct.
Semiconductors are all around us but perhaps are less obvious than conductors or insulators. Semiconductors use include:. Insulators have a wide range of applications from everyday use through to specialist and high-tech industrial applications. Insulators include:. Our range of products is specifically designed to exploit the unique thermal and electrical insulating properties of the mineral.
The Elmelin range includes mica sheets, mica rolls, mica laminates, specialist electrical insulation as well as other manufacturing requirements. Phlogopite mica sheet grades, MFSSP are particularly useful in the automotive and aerospace industries. Mica can be found in heat shields, as well as in the interiors and exteriors of aircraft.
Mica also provides thermal runway and flame-retardant barriers in vehicles such as cars, trucks, trains and busses. Muscovite mica sheets MFSSM come in fully flexible or semi-flexible form and offer a combination of thermal insulation and voltage insulation. Muscovite is more commonly found in everyday equipment due to its dielectric applications, which include capacitors. The foundry and steel industries are particularly reliant on the thermal insulation and the dielectric properties of mica.
In their rigid form, mica sheets are used in constructing furnaces, as they are cost-effective and they stably provide resistance against high temperatures.
Resistivity of conductors insulators and semiconductors pdf merge
Conductors, insulators and semiconductors
Conductors are generally substances which have the property to pass different types of energy. In the following, the conductivity of electricity is the value of interest. The conductivity of metals is based on the free electrons so-called Fermi gas due to the metal bonding.
In physics and electrical engineering , a conductor is an object or type of material that allows the flow of charge electricity through them.
15 Difference Between Conductor, Insulator And Semi-Conductor With Examples
The conductors always conduct electric current while the insulators do no conduct. Most common electrical conductors are made from metals. Such materials allow the current flow due to the presence of free electron or ions which starts moving when voltage is applied.
Materials are classified as conductors , insulators , or semiconductors according to their electric conductivity. The classifications can be understood in atomic terms. Electrons in an atom can have only certain well-defined energies, and, depending on their energies, the electrons are said to occupy particular energy levels. In a typical atom with many electrons, the lower energy levels are filled, each with the number of electrons allowed by a quantum mechanical rule known as the Pauli exclusion principle. Depending on the element, the highest energy level to have electrons may or may not be completely full. If two atoms of some element are brought close enough together so that they interact, the two-atom system has two closely spaced levels for each level of the single atom.
When no of atoms is combining then the whole energy levels are dividing in sub energy levels and become overlapped. They make a band, which is called energy band. Remember that the energy of free electron is changing continuously. As clear from its name it is that type of band, which is near to the nucleus, and it is completely full from electron. In that type of band there are no free electron.