Indium
A soft, silvery post-transition metal recovered mainly as a byproduct of zinc refining. Essential feedstock for indium tin oxide (ITO) transparent conductors, low-melting solders and compound semiconductors used in automotive displays, sensors and electronics.
Overview
Indium (symbol In, atomic number 49) is a soft, ductile post-transition metal with a density of about 7.31 g/cm³ and a melting point of 156.6°C. It is rarely mined as a primary ore; more than half of global supply is recovered from zinc sulfide concentrates, with China and the Republic of Korea dominating refined output. In automotive programmes, indium is not used as a structural metal but as a critical electronic and optical precursor. Indium tin oxide (ITO) remains the industry-standard transparent conductive oxide for touchscreens, instrument-cluster displays, HUD combiner coatings and capacitive switch surfaces. Soft indium and indium-alloy solders enable low-temperature bonding of sensors, LEDs and power modules where thermal budgets must stay below typical SAC soldering windows. Indium phosphide and related III–V compounds support high-speed photodetectors and laser diodes for LiDAR and optical interconnects. Supply concentration, growing display content per vehicle and limited end-of-life recovery place indium on EU and US critical raw material watchlists for electronics-heavy platforms.
Automotive Applications
Similar Materials
Antimony
Metalloid
A lustrous, brittle grey metalloid primarily used as an alloying agent to harden lead and as a chemical synergist in flame retardants.
Tin
Post-transition Metal
Tin is a soft, corrosion-resistant post-transition metal used as the base metal for solders, tinplate coatings and bronze alloys. This entry covers elemental and primary tin feedstock, separate from specialised tin-silver solder alloy grades.
Beryllium
Alkaline Earth Metal
Elemental beryllium is a lightweight alkaline earth metal with exceptional stiffness-to-weight and thermal stability, used in aerospace structures, precision optics and specialised electronics. It is distinct from beryllium-copper (BeCu) alloys and carries significant toxicity and regulatory controls.
Germanium
Metalloid
A brittle, silvery-grey metalloid recovered mainly as a byproduct of zinc and coal processing. Critical for infrared optics, fibre optics and compound semiconductors used in ADAS, LiDAR and night-vision systems.
Properties
Category
Type
Post-transition Metal
Available Colors
Available Forms
Key Properties
- Soft, highly ductile post-transition metal
- Forms ITO transparent conductive oxide films
- Low melting point (~156.6°C) for specialty solders
- Excellent wetting and cold-welding behaviour
- Critical for touch and display stacks
- Supply concentrated as zinc refining byproduct
Technical Specifications
Density
7.31 g/cm³
Tensile Strength
Not typically used as a structural metal (soft post-transition metal)
Temperature Resistance
Melts at 156.6°C; ITO films stable through typical automotive display and cabin thermal envelopes
Sustainability
Sustainability Rating
Primary supply depends on zinc smelting byproducts with high geographic concentration in China and Korea. Manufacturing scrap from ITO sputtering targets is routinely recycled, but post-consumer recovery from automotive and consumer displays remains limited. Listed among critical raw materials due to supply risk and rising electronic content per vehicle.