Subject and UNIT: Physics for Electronics Engineering: Unit III: Semiconductors and Transport Physics
A semiconductor in extremely pure form is known as intrinsic semiconductor. Its electrical conductivity is changed only by thermal excitation.
Classifications, Types
Subject and UNIT: Physics for Electronics Engineering: Unit III: Semiconductors and Transport Physics
The lower curves represent energy and momentum values of holes in valence band of semiconductor. Similarly upper curves denote corresponding values for electrons in conduction band.
Definitions, Properties, Classification, Example, Characteristics, Uses
Subject and UNIT: Physics for Electronics Engineering: Unit III: Semiconductors and Transport Physics
Semiconducting material has electrical conductivity between a good conductor and a good insulator. It is simply called semiconductor. It is a special class of material which is very small in size and sensitive to heat, light and electricity.
Physics for Electronics Engineering
Subject and UNIT: Physics for Electronics Engineering: Unit II: Electrical and Magnetic Properties of Materials
Important two marks and 16 marks questions in Magnetic Properties of Materials
Physics for Electronics Engineering
Subject and UNIT: Physics for Electronics Engineering: Unit II: Electrical and Magnetic Properties of Materials
Important Solved Problems in Magnetic Properties of Material
Subject and UNIT: Physics for Electronics Engineering: Unit II: Electrical and Magnetic Properties of Materials
A device that woks on the principle of the GMR is a spin valve. This device is used in magnetic hard discs for high density data storage. There are 4 layers altogether in a spin valve
SQUID, Transistor(QUIT), Magneto resistance(GMT)
Subject and UNIT: Physics for Electronics Engineering: Unit II: Electrical and Magnetic Properties of Materials
When the magnetic field is applied perpendicular to the plane of the ring, the current is induced at the two Josephson junctions. The induced current produces the interference pattern and it flows around the ring so that the magnetic flux in the ring can have the quantum value of magnetic field applied.
Quantum Superposition, Applications
Subject and UNIT: Physics for Electronics Engineering: Unit II: Electrical and Magnetic Properties of Materials
It is a fundamental principle of quantum mechanics. It states that much like waves in classical physics, any two (or more) quantum states can be added together ("superposed") and the result will be another valid quantum state.
Exchange Interaction and Ferromagnetism
Subject and UNIT: Physics for Electronics Engineering: Unit II: Electrical and Magnetic Properties of Materials
Certain metals like iron (Fe), cobalt (Co), nickel (Ni) and certain alloys exhibit high degree of magnetisation. These materials show the spontaneous magnetization i.e., they have magnetisation (atomic magnetic moments are aligned) even in the absence of an external magnetic field.
Derivation
Subject and UNIT: Physics for Electronics Engineering: Unit II: Electrical and Magnetic Properties of Materials
According to Langevin's theory the paramagnetic susceptibility is inversely proportional to the temperature. However, some metals have been found to exhibit paramagnetism independent of temperature.
Subject and UNIT: Physics for Electronics Engineering: Unit II: Electrical and Magnetic Properties of Materials
Magnetic materials are classified into two categories based on existence of dipole moment and the response of magnetic material to external magnetic fields
Basic Definitions
Subject and UNIT: Physics for Electronics Engineering: Unit II: Electrical and Magnetic Properties of Materials
A very large number of modern devices depend upon magnetic properties of materials for their working. For example, the speakers, electrical power generators, electrical machines, transformers, television, data storage devices like magnetic tapes and disks, magnetic compass etc.