Indium, having the symbol In and with the atomic 49, is a chemical element that has been categorized in the poor metal group. In the periodic table, indium is placed in group 13. This chemical element has several applications, especially in the manufacture of LCD (Liquid Crystal Display). Most of this element produced is consumed in the LCD market every year. However, majority of the consumers only have indirect interaction with indium, as it forms components of bigger products. Indium has a tendency to be an expensive element as it is available rarely. This element derived its name from the Latin term "indicum", which in English means violet or indigo.
Often indium is found along with silver and zinc ores in nature. Pure indium is extremely soft and has a silver-white hue and is highly malleable. Even in its pure form, this element is not considered to be toxic. However, some compounds of indium may be detrimental for our health. Several such compounds are believed to carcinogenic and even when used in miniscule amounts they are likely to lead to damage of various organs.
In 1863, German chemists Hieronymus Theodor Richter and Ferdinand Reich discovered indium. It seems indium was discovered while these two chemists were working to isolate substances present in zinc ores. This element got its name for its typically indigo hued line present in the element's atomic spectrum. Many years after the two German chemists discovered indium, Richter was successful in isolating this element. However, it is interesting to note that actually Reich was color blind. He worked with Richter mainly because the latter would be able to make observations that especially depended on color perception.
Indium has several industrial applications. For instance, this element is used for plating various materials such as bearings and other moving parts. In addition, this element is also utilized for plating silver and also in the manufacture of transistors, particularly as solder. Moreover, this element as well as its compounds is also used by the semiconductor industry. It is also found in a number of medical imaging. Wires made from indium may be utilized for creating seals in a variety of applications as well. Indium has the ability to resist corrosion very well and several of this element’s uses utilize this property of the element.
Usually indium is considered to be a mining industry's by-product because it is found along with other metal ores - such as silver and zinc. Expressed in a different way, mining companies usually don't look to mine indium. But while mining other minerals, they get indium as a bonus that increases their profits.
Most of the supply of indium globally comes from the mining centers in Canada. In fact, it was very difficult to locate pure form of indium till 1924. However, while the electronic waste is increasing rapidly worldwide, this waste material, instead of being discarded is being recycled to extract indium. This, in turn, has decreased the pressure on the global indium market as much of the element being used today is being obtained from this electronic waste.
Indium has a number of therapeutic applications. This element is said to improve the hormonal balance of the body and also enhance the immune system. In turn, this helps to enhance a person's capability to fight against a range of ailments.
Moreover, scientists have already proved that this element has a positive effect on the pituitary glands as well as the hypothalamus. The hypothalamus and the pituitary glands are the main producers of hormones in our body. In addition, they also help to maintain the production of nearly all hormones and their maintenance in the human body.
Indium also has the ability to rejuvenate as well as energize a person. Moreover, this element has been found to be effective in alleviate the problems associated with attention deficit disorder (ADD), managing autism, promoting a healthy body weight, regulating the blood pressure and enhancing the health of the skin.
However, different from many of the minerals, indium is generally not found in the foods we consume. This element needs to be taken externally as a supplement. Ideally, the water-soluble form of indium should be taken orally.
Our body absorbs indium and also helps the body to absorb various other minerals like copper, chromium, manganese and zinc. All these minerals help the body to look younger and also perform other functions and, hence, they are essential minerals. In due course, people who take indium supplement are known to have reported less stress, better levels of blood pressure and considerable weight loss.
Aside from the therapeutic uses of indium, the oxides of this element as well as indium tin oxide are utilized in the form of a transparent coating that is conductive. These substances are applied to substrates of glass to make electroluminescent panels like LCD and touch screens. In addition, indium oxide is also utilized in the form of a light filter in low pressure sodium vapour lamps. When this oxide is used in sodium vapour lamps in this manner, it works to reflect light into the lamp, thereby making the lamp more effectual.
Indium compounds such as indium nitrate, indium phosphide and indium antimonide are usually employed as semiconductors. In addition, this element is utilized to make the semiconductor called copper indium gallium selenide (CIGS). All these semiconductors made from indium compounds are used in the manufacture of solar cells with thin films. Indium is also used in laser diodes and LEDs.
Often this element is used instead of mercury in manufacture of batteries with the aim of preventing zinc corrosion and, at the same time, to release hydrogen gases. Indium is also utilized in an alloy to make aluminium sacrificial anodes that are used to help put off saltwater from having any effect on aluminium.
Other industrial uses of indium include its use in bonding gold test leads for manufacturing superconductors. In this case, indium is used in the form of a conductive adhesive. Moreover, wires made from indium are utilized in the form of a vacuum seal in various applications like ultra-high vacuum situations and cryogenics. For instance the vacuum seals are like gaskets that deform to fill up spaces.
Indium also finds utility in the alloy called galinstan, which is utilized as a substitute for mercury since this alloy is also in liquid state at room temperature. However, unlike mercury, it is not poisonous. Indium is also utilized in the control rods of nuclear reactors since this element is capable of capturing neutrons at a very high rate.
Similarly, foils made from indium find use in the personal computers where they are utilized as thermal interface material. When these foils melt, they fill up the minute spaces making the personal computer further efficient. In addition, this element is used in medical imaging in the form of a radioactive tracer. Indium gives out radiation and, hence, it is employed for testing the efficacy of antibiotic therapy.
Generally, indium is widely employed in electrical components like high speed transistors, infrared detectors as well as photo-voltaic devices. Indium is also used in solder manufacture and alloys owing to its low melting point and its ability of the element to conduct electricity. In fact, this metal is also widely used as glass coating. Although glasses having indium coatings are transparent, they have a special property - reflecting infrared rays. Such coated glasses are generally used in architectural windows, aircraft windows, ovens, refrigerators and even in doors.
Very often indium tin oxide is employed in sodium lamps with low pressure. The neutrons of this element are used in the control rods of nuclear reactors. It also has application in nuclear medicine. As the name suggests, in this field, indium leukocyte scintrigraphy is employed to monitor the white blood cells' (leukocytes) functioning.
In addition, owing to the metal's ability to fill up the gaps in coefficient of thermal expansion (also known as CTE) of two dissimilar metals, indium is utilized in the form of a solder alloy. Indium helps to fill up the gaps caused by breakage at the joints due to dissimilarity of the metals, which expand and contract differently.
As more and more LCD screens are being used in various types of media and medical setups, it can be presumed that the use of this metal will increase manifold in the future. On the other hand, the supply and price of indium would largely depend on the metal's commercial availability.
As of now, China produces almost 60 per cent of the world's total production of indium. As a result, the US has to depend on China and other indium producing nations to meet its requirements of this metal.