Indium

7.31
114.818
[Kr] 4d105s25p1
115In
13
5
p
49
2, 8, 18, 18, 3
558.299
In
7.31
156.60°C, 313.88°F, 429.75 K
2027°C, 3681°F, 2300 K
Ferdinand Reich and Hieronymous Richter
1863
7440-74-6
4514408
More Information
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Uses and Properties

Image Explanation

Indium tin oxide remains a widely used material in the production of touchscreens. This material is essential for the functionality of touchscreens and other display technologies.

Appearance

A soft, silvery metal that is stable in air and water.

Uses

Unveiling the Versatility of Indium: From Touchscreens to Beyond


In the realm of modern technology, certain elements play a pivotal role in shaping the devices we use daily. One such element that quietly but significantly contributes to our digital experiences is indium. This unassuming metal, with its unique properties, has found a myriad of applications, with touchscreens being just the tip of the iceberg.

 

Indium in Touchscreens: Powering Your Digital Touch Experience


When you tap, swipe, or pinch on your smartphone or tablet screen, you're likely interacting with a layer of indium tin oxide (ITO). This transparent and conductive material is applied as a thin film on glass surfaces, forming an integral part of capacitive touchscreens. The conductivity of indium tin oxide allows for the detection of changes in capacitance when you touch the screen, enabling seamless and responsive interactions.

Moreover, ITO's transparency in the visible light spectrum ensures that your display remains clear and vibrant. This unique combination of conductivity and transparency makes indium a cornerstone in the world of touch-sensitive devices, revolutionizing the way we interact with technology.

 

Beyond Touchscreens: Exploring Indium's Diverse Applications


While touchscreens represent one of the most prominent uses of indium, this versatile element extends its reach far beyond our handheld devices.

  1. Solar Panels: Indium is a key component in thin-film photovoltaic technologies, enhancing the efficiency of solar panels. Its application in copper indium gallium selenide (CIGS) solar cells allows for flexibility, making it possible to integrate solar panels into various surfaces.

  2. LEDs and Display Technologies: Indium-based materials are crucial in the production of light-emitting diodes (LEDs). Indium gallium nitride (InGaN) is commonly used in blue and green LEDs, contributing to the vibrant colors displayed in various electronic devices, including televisions and computer monitors.

  3. Semiconductor Industry: Indium finds applications in the production of semiconductors, where it is used in the manufacturing of transistors and other electronic components. Its unique properties, such as low melting point and excellent thermal conductivity, make it an ideal material for certain semiconductor processes.

  4. Alloys and Solders: Indium is often alloyed with other metals to create materials with specific properties. Indium-based alloys are used in solders for electronics assembly, ensuring reliable connections in electronic circuits.

  5. Medical Imaging: Indium-111, a radioactive isotope of indium, is utilized in nuclear medicine for diagnostic imaging. It is commonly used in radiopharmaceuticals for imaging white blood cells and detecting infections.


 

The Future of Indium: Innovations and Sustainability


As technology advances, researchers and industries are constantly exploring ways to optimize materials and processes. While indium has proven invaluable in various applications, there is a growing awareness of its relative scarcity and the need for sustainable practices.

Efforts are underway to develop alternative materials and technologies that can replicate or improve upon indium's properties. This includes research into new transparent conductive materials for touchscreens and exploring alternative materials in solar panel technologies.

In conclusion, indium has earned its place as a silent hero in the world of technology. From enhancing our daily interactions with touchscreens to contributing to the efficiency of solar panels and the brilliance of LEDs, indium's versatility knows no bounds. As we continue to push the boundaries of innovation, the role of indium in shaping the future of technology remains a compelling and ever-evolving story.

History

In the vast tapestry of the periodic table, nestled between cadmium and tin, lies a unique and versatile metal with a history as fascinating as its properties. Enter Indium, denoted by the symbol "In," a precious element that has quietly shaped industries and technologies since its discovery in the late 19th century.

 

Discovery and Early Years: Unraveling the Origins


The tale of Indium begins in 1863 when German chemists Ferdinand Reich and Hieronymous Theodor Richter discovered the element while examining zinc ores. The duo noticed unusual spectral lines during their analysis, indicating the presence of an unknown element. They named their discovery "Indium," inspired by the indigo-blue lines prominent in its spectrum.

In the years that followed, Indium's rarity became apparent. It was primarily extracted as a byproduct of zinc ore processing, making it a somewhat elusive and precious resource. However, its unique properties soon caught the attention of the scientific community, paving the way for a multitude of applications.

 

The Pioneering Years: Indium Finds Its Niche


As the 20th century unfolded, Indium's applications diversified. Its low melting point, exceptional thermal conductivity, and malleability made it an ideal candidate for various industrial uses. The emergence of alloys, particularly Indium-based ones, played a crucial role in the production of low-temperature solders used in electronics.

During World War II, Indium found itself on the front lines of technological innovation. Its incorporation into soldering applications facilitated the production of reliable electronic equipment, aiding the war effort and solidifying Indium's status as an indispensable material in the burgeoning electronics industry.

 

The Electronic Revolution: Indium in the Semiconductor Age


The post-war era witnessed the rise of the semiconductor industry, and Indium played a vital role in this technological revolution. Its inclusion in the manufacturing of semiconductors and transistors contributed to the miniaturization of electronic components, paving the way for the development of smaller, more powerful devices.

In the latter half of the 20th century, Indium's conductivity and transparency found a new frontier—liquid crystal displays (LCDs). The advent of flat-panel displays in televisions, computers, and other electronic devices propelled Indium into the spotlight once again, as Indium tin oxide (ITO) coatings became the standard for creating transparent conductive films crucial for touchscreens.

 

The Radiant Future: Indium in the 21st Century


As we venture into the 21st century, Indium continues to play a pivotal role in shaping emerging technologies. Its deployment in photovoltaic applications, particularly in thin-film solar cells, has contributed to advancements in renewable energy. Indium-based alloys are also instrumental in enhancing the efficiency of next-generation solar panels.

Moreover, Indium's use in light-emitting diodes (LEDs) has illuminated our world with energy-efficient and vibrant displays. The production of blue and green LEDs, crucial for various electronic devices and lighting applications, relies on the unique properties of Indium gallium nitride (InGaN).

 

Challenges and Opportunities: Navigating the Future of Indium


While Indium has undoubtedly left an indelible mark on the pages of technological history, challenges loom on the horizon. The metal's relative scarcity and the increasing demand for electronic devices have spurred efforts to explore alternative materials and sustainable practices.

Researchers and industries are actively engaged in finding solutions to reduce dependence on Indium, whether through recycling initiatives or the development of new materials. The story of Indium is one of resilience and adaptation, and its future chapters will undoubtedly be shaped by the collective efforts of scientists, engineers, and innovators.

In conclusion, Indium's journey from a spectral curiosity to a cornerstone of modern technology is a testament to the indomitable spirit of human ingenuity. As we continue to unlock the secrets of the elements, Indium stands as a shining example of how a humble metal can transcend its origins and become an integral part of the technological tapestry that defines our world.

Atomic Data

Atomic Radiues, Non-bonded (A): 1.93
Electron Affinity (kJ mol-1): 28.9
Covalent Radiues (A): 1.42
Electronegativity (Pauling Scale): 1.78
Ionisation Energies (kJ mol-1) 1st 2nd 3rd 4th 5th 6th 7th 8th
558.299 1820.707 2704.48 5210 - - - -

Oxidation States and Isotopes

Common oxidation states 3
Isotope Atomic Mass Natural Abundance Half Life Mode of Decay
115In 114.904 95.71 4.4 x 1014 y β-

Supply Risk

Relative Supply Risk: 7.6
Crustal Abundance (ppm): 0.052
Recycle Rate (%): <10
Production Conc.(%) : 53
Top 3 Producers:
1) China
2) Republic of Korea
3) Japan
Top 3 Reserve Holders:
Unknown
Substitutability: Low
Political Stability of Top Producer: 24.1
Political Stability of Top Reserve Holder: Unknown

Pressure and Temperature Data

Specific Heat Capacity: 233
Shear Modulus: Unknown
Young Modulus: Unknown
Bulk Modulus: Unknown
Pressure 400k Pressure 600k Pressure 800k Pressure 1000k Pressure 1200k Pressure 1400k Pressure 1600k Pressure 1800k Pressure 2000k Pressure 2200k Pressure 2400k
- 8.31 x 10-11 1.08 x 10-5 0.0127 1.413 40.9 - - - - Unknown

Podcast

Transcript :



Indium is a chemical element with the symbol, I, n, and atomic number 49. It is a good example of the fact that a small amount of something can make a big difference. For instance, a small amount of Indium can be added to gold alloys to make them harder. Utilization of indium in the nuclear sector resulted in a dramatic rise in price. However, after the Three Mile Island nuclear accident of 1979, the demand for Indium declined. In the composition of indium tin oxide, it plays a critical role in the functioning of the global economy. However, the cost of Indium is high. So, its price fluctuates frequently. Due to recent changes in demand, Indium prices have increased. It is estimated that the current Indium primary resource is 356,000 tons.

In 1863, two German scientists named Ferdinand Reich and Hieronymus Theodor Richter made the discovery that indium existed. They had been working on a study of zinc mineral blend. One of their samples contained an indigo-colored line. Upon examining the spectrum of this sample, they decided that the element was a new and promising metal. The discovery of Indium was announced by Reich and Richter in their paper, titled "The Emission of Indium from Zinc Ore". Afterwards, they realized that the metal was a real element. Later, Richter checked the spectrum and noticed a rich violet-blue line. This spectral line was the first to suggest the existence of indium. After the discovery, the first patents to process Indium were granted. The first commercial quantities were produced in Kingman in the US, in 1926.

Indium occurs in trace amounts in zinc ores. However, its production volume is relatively low compared to other products. It is found in lead ores as well. These ores may contain up to one percent of indium. In the 19th century, it was difficult to extract Indium from ores. But in the early 1920s, a new process by Daniel Grey enabled its extraction. This led to the founding of the Indium Corporation in 1934. The United States Geological Survey agency, lists several Indium producers. These are the United States, Canada, Japan, China, Russia, Germany, Australia, Bolivia, South Africa and Afghanistan. Some of these countries have closed their operations. During the last decade, China has significantly expanded its production. As of 2005, China was producing more than 60% of the world's indium.

According to the USGS, the most common Indium isotope is Indium 115. This is a stable isotope that is very slow to decay. During the last decade, the recovery of Indium from production waste has become of high interest.

Indium is a silvery white metallic element. It is soft, malleable, very ductile and easily scratched, and formable with excellent corrosion resistance and conductivity. Indium reacts directly with sulfur and halogens. However, it is not very toxic. The melting point of Indium is 313.9 degrees Fahrenheit. When burned, Indium turns into a bright violet flame.

The indium crystal structure is tetragonal. It features a face-centered, somewhat deformed cubic structure. As a result, the crystal is easy to bend. This property makes Indium useful as a solder. Moreover, it is stable to both air and water, and is easily manipulated into any shape.

Indium is an essential element that plays an important role in a wide range of industries. It is found in many common products, including metals, batteries, and electronic circuits. This element is also used in medical and dental equipment. Indium is most commonly used in Indium tin oxide, which is used in LCD´s screens, touch panels and monitors. Indium tin oxide can be deposited as a thin film on glass and polyethylene terephthalate. It is used in low-melting fusible alloys, in solders and in bearing lubricants for aircraft in the manufacturing of fire-door links and sprinkler heads. In the electronics industry, Indium is used to form a corrosion-resistant mirror surface and as a protective coating for metal surfaces. It is also used in Copper Indium Gallium Selenide, named CIGS thin-film solar cells. This element is a common component in alkaline batteries.

Additionally, it may be used in the organic synthesis such as in the Reformatsky reaction or Barbier reaction. An important use of Indium is in the control rods of nuclear reactors. It has a large cross section for the trapping of thermal neutrons. One of the major applications of Indium is in the manufacture of semiconductors. However, its production volume is relatively low compared to other products.

References


  • W. M. Haynes, ed., CRC Handbook of Chemistry and Physics, CRC Press/Taylor and Francis, Boca Raton, FL, 95th Edition, Internet Version 2015, accessed December 2014.

  • Tables of Physical & Chemical Constants, Kaye & Laby Online, 16th edition, 1995. Version 1.0 (2005), accessed December 2014.

  • J. S. Coursey, D. J. Schwab, J. J. Tsai, and R. A. Dragoset, Atomic Weights and Isotopic Compositions (version 4.1), 2015, National Institute of Standards and Technology, Gaithersburg, MD, accessed November 2016.

  • T. L. Cottrell, The Strengths of Chemical Bonds, Butterworth, London, 1954.

  • John Emsley, Nature’s Building Blocks: An A-Z Guide to the Elements, Oxford University Press, New York, 2nd Edition, 2011.

  • Thomas Jefferson National Accelerator Facility - Office of Science Education, It’s Elemental - The Periodic Table of Elements, accessed December 2014.