Does Tungsten Conduct Electricity? 11 Facts You Should Know


Tungsten is a very hard and heaviest metal. It is the rarest element found naturally. Let us focus on the electrical conductivity of tungsten.

The electrical conductivity of the tungsten depends on the temperature. Tungsten can conduct electricity at high temperatures. In normal conditions, tungsten does not offer any electrical conductivity because of its resistive heat property.

Tungsten has a high melting point among all the metals in its purest form, which is one of the advantages for its electrical conductivity. Let us discuss some facts that contribute to electrical conductivity in tungsten in this post.

How does tungsten conduct electricity?

The flow of mobile electrons on the metal surface determines the electrical conductivity. Let us focus on the process of electrical conductivity in tungsten.

The electric conduction occurs in tungsten by free valence electron in its outer core. These free electrons carry charges along the tungsten for electrical conduction in all directions. The free electrons are available for conduction only when the tungsten temperature is a bit higher than normal.

Outer shell valence electrons of tungsten
Image credits: Wikimedia commons

The tungsten does not allow any charges to conduct electricity at low temperatures even though it consists of free electrons because of its resistive property which retards the motion of electrons.

Why does tungsten conduct electricity?

Some properties such as melting point and stability can contribute to electrical conduction in the material. Let us discuss the reason for electrical conductivity in tungsten.

Tungsten conducts electricity because of heat resistivity. The increase in temperature does not make any difference for electrical conduction in tungsten. As the temperature rises, the electron’s motion becomes more random in every direction leading to electrical conduction.

Another reason for the electrical conductivity in tungsten is the low vapor pressure offered by them.

What is the electrical conductivity of tungsten?

Any metal which allows maximum charges to flow across them describes the electrical conductivity of that metal. Let us know the electrical conductivity of tungsten.

The electrical conductivity of tungsten is approximately measured as 8.9×106 Sm-1. Since tungsten can be electrically conductive only at high temperatures, at a temperature of 20°C, the electrical conductivity of tungsten is 1.76×107 Sm-1, which is indeed a good electrical conductive value.

Is tungsten a good conductor for electricity?

Metals are a good electrical conductor because their lattice atom consists of more free electrons. Let us discuss about electricity conduction in tungsten.

Tungsten is a good conductor for electricity only at high temperatures because of its thermal stability. At higher temperatures population of conduction electrons increases. At low temperatures, the electrical conductivity of tungsten is very low.

Why is tungsten a poor electric conductor than copper?

The electrical conductivity of the metals is characterized by resistivity for electron flow. Let us reason out the poor conductivity of tungsten compared to copper.

The electrical resistivity is more in the tungsten than the copper because the restriction offered by the tungsten to electric charges to flow is more than the copper, and the charge flows for conduction is more in copper than tungsten. This makes tungsten a poor electric conductor than copper.

Structure and bonding of tungsten

Tungsten is brittle steel-gray metal with high tensile strength. Let us learn the structure and bonding of tungsten.

  • Structure of tungsten –It has two crystalline structures called α, which has body-centered cubic geometry, and β form possessing an A15 cubic structure. α is the stable form of tungsten
  • Bonding of tungsten –A strong metallic bond exists between the atoms of tungsten by 5d electrons.
Occurrence of Metallic bond in tungsten
Image credits: Wikimedia Commons

Is tungsten a good conductor of heat and why?

The amount of heat that flows through metal determines the thermal or heat conductivity. Let us illustrate the capacity of heat conduction in tungsten.

Tungsten is a poor conductor of heat. Tungsten offers low thermal expansion, which is intended to offer high resistivity for the heat to flow through it. The high melting point of tungsten also makes them a poor conductor of heat.

Why tungsten is used in electric bulb?

The metals used for the electric purpose must have a property like high tensile strength. Let us illustrate which property of tungsten helps them use in electric bulbs.

Tungsten is a filament in an electric bulb because it has some remarkable property called incandescence, where the filament will heat up to sufficient temperature and emit visible light without melting. A vacuum bulb covers the filament of tungsten because of this incandescence.

Another reason tungsten is used in electric bulbs is its resistivity and high melting. A good conductor of electricity must possess some resistivity to dissipate power. Tungsten won’t melt at incandescence temperature in a vacuum, while most metals melt easily.

Does tungsten carbide conduct electricity?

Tungsten carbide is an alloy obtained by heating carbon black with tungsten in the presence of hydrogen. Let us focus on the electric conductivity of tungsten carbide.

Tungsten carbide can conduct electricity because of the cobalt content in the sample. Cobalt is used as a binder to prepare the tungsten carbide, which provides toughness. As the cobalt content increases, the electrical conductivity also increases.

Another reason for good electrical conduction in tungsten carbide is that it offers high electric resistivity. The electrical conductivity of tungsten carbide is 10% lesser than that of copper. Sometimes nickel is also used as a binder, contributing to its electrical conductivity.

Does tungsten ring conduct electricity?

A Tungsten ring is a form of tungsten carbide molded into the desired ring structure. Let us illustrate the electrical conductivity of the tungsten ring.

Tungsten rings do not conduct electricity even though it is a tungsten carbide mold. When tungsten carbide is powdered and molded to form a ring, it loses metallic property and becomes cemented carbide. The tungsten ring is a ceramic that does not allow any charges to flow through it.

Does tungsten oxide conduct electricity?

Tungsten oxide is a monoclinic thin film of tungsten and oxygen. Let us illustrate the property of the electrical conduction of tungsten oxide.

Tungsten oxide is a good conductor of electricity because of the void created when oxygen is exposed to tungsten. When oxygen is exposed to tungsten, oxygen vacancy occurs because the number of tungsten atoms is higher than the oxygen atom. This conductivity is similar to that of semiconductors.

The void created by oxygen vacancies tends to behave as a semiconductor due to the band gap because of oxygen vacancy. The electrical conductivity of tungsten oxide is temperature-dependent. The rise in the temperature decreases the band gap leading to more conductivity.

Conclusion

Let us wrap up this post by stating electric conductivity of tungsten is temperature dependent quantity which rises with increase in temperature. The heat resistivity of tungsten contributes for electrical conductivity at high temperature.

Keerthi Murthi

I am Keerthi K Murthy, I have completed post graduation in Physics, with the specialization in the field of solid state physics. I have always consider physics as a fundamental subject which is connected to our daily life. Being a science student I enjoy exploring new things in physics. As a writer my goal is to reach the readers with the simplified manner through my articles. Reach me – keerthikmurthy24@gmail.com

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