What is the relationship between the conductivity of non metallic materials and temperature

The relationship between conductivity and temperature depends on the conductor first!

If the conductor is metal, the higher the temperature, the stronger the conductivity. This is because the free charge increases with temperature!

If the conductor is an electrolyte, the higher the temperature, the worse the conductivity. This is because the speed of ion activity increases, and more energy is needed to change!!

If you have any electrical questions, you can ask me!!

The law of scales "determines the correlation between the key parameters of a system, pointing out the basic mechanisms that determine the behavior of the system." This law is important in biology, for example, a "scaled relationship" between body mass and metabolic speed spans 21 orders of magnitude. "Scale relations" are also important in the physical sciences.

The discovery of high-temperature superconductivity in cuprate materials has led to in-depth research on these materials and related composite oxides. However, there is no universal "scaling law" that relates the fundamental properties of these materials, such as superfluid density and superconducting temperature, at least not for optimized adulterated materials. But now a general "scale relation" has been found, linking superfluid density, conductivity, and critical temperature, with conductivity decreasing with increasing temperature.

The relationship between the conductivity and temperature of non-metallic materials is that it presents a negative temperature coefficient of resistance, while metals present a positive temperature coefficient of resistance, which is the essential difference between metals and non-metals, and is also the standard for judging metals and non-metals. The so-called negative temperature coefficient of resistance refers to the phenomenon that the resistance decreases as the temperature increases.

The conductivity of non-metallic materials is the opposite of that of metals, and the better the conductivity as the temperature increases. But this, like metal, is not absolute, and there are exceptions.

Graphite is a non-metal, but it has good electrical conductivity.

Graphite is an allotrope of carbon, which is gray-black, opaque solid, chemically stable, corrosion-resistant, and not easy to react with acids, alkalis and other agents. It is burned in oxygen to produce carbon dioxide, which can be oxidized by strong oxidants such as concentrated nitric acid, potassium permanganate, etc. It can be used as an anti-wear agent, lubricant, high-purity graphite is used as a neutron moderator in atomic reactors, and can also be used to manufacture crucibles, electrodes, brushes, dry batteries, graphite fibers, heat exchangers, coolers, electric arc furnaces, arc lamps, pencil refills, etc.

Graphite is a non-metal, but it has good electrical conductivity.

The electrical conductivity of graphite is a hundred times higher than that of ordinary non-metallic minerals. Thermal conductivity exceeds that of metallic materials such as steel, iron, and lead. The thermal conductivity decreases with increasing temperature, and even at extremely high temperatures, graphite becomes an insulator.

Graphite is able to conduct electricity because each carbon atom in graphite forms only 3 covalent bonds with other carbon atoms, and each carbon atom still retains 1 free electron to transport the charge.

The material that is not metallic but has good electrical conductivity is Si silicon.

Silicon accounts for about the total weight of the earth's crust, second only to oxygen. In nature, silicon is usually found in the form of oxygenated compounds, the simplest of which is silica siO2, a compound of silicon and oxygen. Quartz, crystal, etc. are variants of pure silica.

The silicon-oxygen compounds in ores and rocks are collectively referred to as silicates, and the more important ones are feldspar KalSi3O8, kaolin Al2Si2O5 (OH)4, talc MG3 (Si4O10) (OH)2, mica kal2 (Alsi3O10) (OH)2, asbestos H4MG3Si2O9, sodium zeolite Na2 (Al2Si3O10)·2H2O, garnet CA3Al2 (SiO4)3, Zircon, quartz, ZRSIO4 and beryl, BE3AL2SI6O18, etc. Soil, clay and sand are the products of weathering of natural silicate rocks.

The essence of high conductivity of non-metals is that they are connected by ionic bonds or covalent bonds, and from the physical properties, most of the non-metals are insulators, and only a few non-metals are conductors (carbon) or semiconductors (silicon).

Because the electrons or carriers in non-metallic materials allow the song to increase in temperature, the ability to move is enhanced, and the ability to transfer electric charge is enhanced, and the conductivity increases.

Physical properties: Most of the non-metallic elements are molecular crystals, and a few are atomic crystals and transitional layered crystals.

The number of elemental covalent bonds is mostly in accordance with the 8-n rule:

1. Noble gas: 8-8=0 (2-2=0), which is a monoatomic molecule.

2. Halogen, hydrogen: 8-7=1 (2-1=1), is a diatomic molecule.

3. Sulfur, selenium and tellurium of the VIA group: 8-6=2, which are the chain and ring molecules of the two-coordinated Sizhou.

4. Phosphorus and arsenic of the VA group: 8-5=3, which are three-coordinated finite molecules P4 and As4, and gray arsenic and black phosphorus are layered molecules.

5. Carbon and silicon of group IVA: 8-4=4, which is a diamond-type structure with four coordinations.

The higher the temperature of the metal conductor, the greater the resistance, and the lower the temperature, the lower the resistance.

Superconductivity: When the temperature is reduced to a certain level, the resistance of certain materials disappears.

Resistance temperature conversion formula: r2 = r1 * (t+t2) (t+t1) r2 = x (235 +(40)) 235 + 20) = calculated value 80 A t1 ---winding temperature t--- resistance temperature constant (235 for copper wire, 225 for aluminum wire) t2 --- converted temperature (75 °C or 15 °C) r1 --- measured resistance value r2--- to convert resistance value.

When the temperature variation range is not large, the resistivity of pure metal increases linearly with temperature, that is, = 0(1+ t), where 0 is the resistivity of t and 0 respectively, which is called the temperature coefficient of resistance. Most metallic.

Since the linear expansion is much more significant than that of the metal ( temperature increase 1 , the length of the metal only expands about When considering the change of metal resistance with temperature, its length l and cross-sectional area s can be changed slightly, so r = r0 (1+ t), and the sum of the equation is the resistance of the metal conductor at t and 0 respectively.

The secret to the ease of electrical and thermal conductivity lies in the fact that metals contain electrons that can move freely. The atom has a nucleus composed of neutrons and protons, and there are electrons outside the nucleus, just like the planets in the solar system have their own orbits, and the electrons outside the nucleus also have their own orbits, and the farther away from the nucleus, the less binding force it has on the electrons. The outermost electrons of metals are generally less abundant and tend to break free from their bindings to form free electrons.

Free electrons move irregularly in the metal, and if an external electric field is applied to it, the free electrons will move in a directional manner, and the directional motion of the electrons will form an electric current, which will make the metal conductive, and the metal will have good electrical conductivity. In addition, when the metal is heated, the free electrons of the heated part move violently due to the gain of heat energy, the energy increases, and collides with the metal ions to exchange energy, transferring heat to other regions, so that the metal conducts heat.

The thermal and electrical conductivity of metals is widely used in life, such as the use of frying pans and wires, which are related to these two properties of metals.

We all know that metals have good electrical and thermal conductivity and ductility. This is something we see and take for granted every day, so have you ever wondered why metals have these properties?

The outermost electrons of the metal atom are small, and the outermost valence electrons are easy to break free from the nucleus and become freely moving electrons, and these freely moving electrons form a negatively charged electron cloud, and the metal atoms that lose their electrons become electropositive particles. The electron cloud and the positively charged metal atoms produce an electrostatic attraction, the electrostatic attraction is known as a metal bond, and it is this electrostatic attraction that binds the metal atoms together, and the electron cloud is equivalent to 502 glue. Since the electron cloud can move freely, the metal bond has no directionality and saturation, in human terms, this bond is relatively soft and can be bent and twisted without being destroyed, it is this characteristic of the metal bond that gives the metal good ductility.

As for electrical and thermal conductivity, it also comes down to the free-moving electron cloud. The electron cloud has a good understanding of the effect on electrical conductivity, because electrons can move freely, so under the action of voltage, the electrons will move directionally, and they will naturally conduct electricity, while rubber cannot conduct electricity because there are no charged particles that can move freely. After a part of the metal is heated, the heated part of the atoms and free electrons will move violently, and the free electrons will run around and hit the metal atoms and free electrons of other parts, and then transfer the heat to the past, which is the origin of the good thermal conductivity of metals.

Conductive: Because the metal contains electrons that can move freely, when a voltage is added to both ends of the metal, the positive electrode accumulates positive charges, and the negative electrodes accumulate negative charges, because the same charges attract each other, and the different charges repel each other, forcing the electrons to move directionally, so they can conduct electricity, which is why metals can conduct electricity.

Thermal conduction: Heat conduction relies on free electrons to transfer heat (mainly through the collision between electrons), and the ability of metal nuclei to bind electrons is relatively weak, so it is generally free electrons that move freely in the metal and can conduct heat.

Metal conduction is due to the directional movement of electrons in the metal

The atoms in the metal except for the free electric gondolon also vibrate near their position, and the intensity of this vibration is related to the temperature of the metal, the higher the temperature, the more intense the vibration. At the same time, the greater the chance of collision between the free electron and the atom, the more the directional motion of the electron is hindered, that is, the resistance increases.

Dielectric conduction is the movement of carriers (such as ions, etc.) to form an electric current. An increase in temperature can lead to an increase in the number of carriers, resulting in an increase in electrical conductivity.

Metal conductivity is the movement of (relative) free electrons in a metal crystal between the gaps formed between metal ions. That is, there are channels in the metal that allow electrons to move, and because the metal ions in the metal crystal are constantly moving (vibrating), these channels are curved and appear in narrow areas at any time.

Different solids have different conductive properties, and their conductivity is usually measured by conductivity. Conductivity is defined as the ratio of the electric field strength e applied to a solid to the current density j within a solid.

Experimental studies have shown that the conductance of solids under a not too strong electric field usually obeys Ohm's law, that is, the current density is proportional to the electric field strength and has nothing to do with the electric field strength. For cubic crystals or amorphous materials, conductivity is isotropic and is a scalar quantity.

In general, conductivity may be anisotropic and should be expressed as a second-order tensor. The unit of electrical conductivity is s m. In many cases, the reciprocal of conductivity is a quantity that is more convenient to use, called resistivity, expressed in , and the unit is ·m.