Properties, History and Uses of Indium

Indium can be as a lustrous and silvery metal. This post-transition and ductile material is so malleable and soft that it can easily be scratched with fingernails and even bent into almost any shape. This silver-coloured metal has a tetragonal structure and is available in liquid form at varying temperatures. This makes it quite similar to gallium which belongs to the same group of metals. Both Gallium and Indium have the wet glass ability or the potential of sticking to the surface of the glass they are in contact with. Indium remains stable when it reacts with water and air but dissolves in acids. It transforms into a violet-coloured flame when heated over its basic melting point.

Indium is not found abundantly in nature, and it is worth noting that cultivated areas possess more of this metal than the non-cultivated regions. In nature, this is a rare metal found in the form of trace elements in various other minerals, specifically, lead and zinc. It is through these metals that Indium is obtained typically in the form of a by-product. The estimated availability of Indium in the Earth’s crust is approximately 0.1 ppm or parts per million. It is more abundant than mercury or silver as per reports by the Royal Society of Chemistry. Indium melting point is 156.6°C, which is low for any metal. If heated above this melting point, Indium transforms into an indigo or violet flame. The name of this metal comes from the bright light in indigo colour that it displays in the spectroscope.

Chemical and Physical Properties of Indium

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This image depicts the symbol of Indium. 

The chemical and physical properties of Indium are as follows:

  • Indium melting and boiling point: 156.6°C and 2027°C, respectively.

  • Indium electron configuration: (Kr) 4d105s26p1

  • Indium atomic number: 49

  • Group: 13

  • Period: 5

  • Density: 7.31 g cm-3

  • Relative atomic weight: 114.818

  • Solid key isotopes: 115In

  • State at room temperature: Solid

  • Element categorization: Metal

  • An atomic symbol used in the periodic table of elements: In

  • Count of isotopes or atoms of the same element with a varied count of neutrons: 35 with half-lives, 2 occurring naturally and 1 stable.

  • Most common Indium isotope: In-115

  • Indium boiling point is 3681°for 2300K. This will probably offer you a clearer understanding of the boiling point of the Indium element.

The History of the Discovery of Indium

The well-known chemists from Germany, namely Hieronymus Theodor Richter and Ferdinand Reich discovered Indium in the year 1863. Both Richter and Reich had long been in the lookout of traces of thallium elements in samples of different zinc deposits and ores. It was only when a bright and brilliant indigo line appeared in the spectrum of a sample that the chemists came to know about the existence and the availability of Indium. The metal has the same natural abundance as silver; however, it can be recovered more conveniently and easily than silver because it typically appears along with iron, copper, zinc and lead ores.

Indium Uses

One of the most prominent uses of this metal is as casting for the bearings in high-speed motors. This is because Indium makes way for the even distribution of the lubricating oils used in these motors. The metal is also ideal for doping germanium in the manufacturing procedure of transistors. Indium is even used for making various other electronic elements like thermistors, photoconductors and rectifiers. You can use it for making mirrors that seem to be more reflective in comparison to silver mirrors but have a long shelf life and do not get tarnished very quickly. Indium works out to be the best metal when used for making low melting alloys. At room temperature, an alloy made with 76% gallium, and 24% indium stays in a liquid state.

Other Uses of Indium are as Follows:

  • Used in semiconductor firms for the manufacture of diodes.

  • Used for manufacturing bearings that are moisture-resistant and the ones that improve anti-seizure characteristics.

  • Utilized in different plating applications.

Indium Uses in Everyday Life

In these present times, Indium seems to be one of the essential elements for the economies of the world. ITO or Indium Tin Oxide is widely used in different manufacturing procedures practised at varied industries and even in the everyday life of individuals. This is one form of the element Indium that serves to be one of the best materials for filling the growing requirements of LCDs or liquid crystal displays along with solar panels, TVs, flat screens and touch screens.

Different properties of this element make it ideal for flat panel displays and LCDs. These include transparency, adhering very strongly to glass, conducting electricity, mechanical and chemical corrosion resistance.

FAQ (Frequently Asked Questions)

1. What are Some Unknown Facts about Indium?

Some unknown facts about Indium are:

  • It releases a high-pitched scream when the metal is bent. The scream is quite similar to crackling or the sound of a tin cry.

  • Indium has several similarities to the metal gallium but is an entirely different element when used for making low-melting alloys.

  • Samples of unblended indium elements have been found in Russia.

  • The first widespread use of the metal was for coating the bearings of the high-performance aircraft engines used in the Second World War.

2. What are Indium Health Effects?

There is absolutely no biological importance of the Indium element. When taken in small quantities, Indium can help in stimulating an individual’s metabolism. The majority of the individuals rarely encounter the compounds of this element. However, all the compounds of this metal are highly toxic, and they can come with some of the most dangerous side effects. They damage the liver, kidney and heart and might even be teratogenic. There is not much data available on the side effects of using Indium, and therefore, proper care should be taken when using the element. It does not pose any threat to marine or land life mainly because it is not found abundantly in the environment.