The presentation prepared by the student of the group Marupov Nuruhammad on the subject of electrical engineering and structural materials

What are the types of dielectric materials

Basic concepts of semiconductor materials

• Semiconductor materials and their conduction properties
• The physics of semiconductors and dielectrics is the most important part of modern physics, and the fields of instrument engineering, radio engineering, and microelectronics develop based on its achievements. Semiconductors belong to the group of materials between metals and dielectrics in terms of electrical conductivity, and at T=0 their valence band is occupied by electrons and the width of the forbidden zone is not large (1eV). An atom consists of a nucleus surrounded by a cloud of electrons

General information about magnetic materials

• Magnetic materials are materials that become magnetized in weak magnetic fields and significantly change the value of these fields. Natural magnetite mineral - magnetite (magnetic ironstone) has been known since ancient times. In China, the shaft (arrow) of the magnetic compass was made from it 2,000 years ago. Magnetite is weakly magnetic. In the 19th century K. Ersted, M. Faraday, E. H. Leni, discovered the laws of electromagnetism, B. S. Jacobi created constant current machines, P. N. Yablochkov created an alternating current generator and transformer, M. O. Dolivo-Dobrovolsky discovered three-phase current. After that, a very strong magnetic material, iron, began to be used as a magnet material. Since 1990, iron-silicon steel and iron-nickel alloys have been widely used in telecommunications. The development of the theory of ferromagnetism greatly accelerated the production of new magnetic materials. In the middle of the 20th century, oxide magnetic materials - ferrites appeared.

• The magnetic moment of a magnet points from its south pole to its north pole.
• In a non-uniform magnetic field a current loop, and therefore a magnet, experiences a net force. The force tries to pull an aligned dipole into regions where the magnitude of the magnetic field is larger and push an anti-aligned dipole into regions where magnitude the magnetic field is smaller. If the magnetic field is pointing into the z-direction, the force on a magnetic dipole in that field is given by Fz = μzΔBz/Δz.