INDIUM                                         Pure Indium 

element 49

Indium was discovered in 1863 by German chemists Ferdinand Reich and Hieronymus Theodor Richter.  They were researching Thallium, and came across indigo streaks that were not known to be present in Thallium.  They realized that it was a new element, and named it Indium after the indigo streaks.

An Indium Antimonide thermal infrared imaging camera

Data about my new favorite element:  Indium

Atomic number:  49

Atomic mass:  114.818 amu

Common isotopes:  ¹¹⁵In (atomic mass: 112.90 amu) accounts for 95.71% of all In

                                        ¹¹³In (atomic mass: 114.90 amu) accounts for 4.29% of all In

Ground state electron configuration: [Kr]5s²4d¹⁰5p¹ ----face-centered tetragonal

Common oxidation states: I, II, and III

            For example:  InCl, InCl₂, InCl₃

Physical appearance:

            Color:  silvery lustrous gray

            State:  Solid at 298K

            Highly malleable and ductile--can be drawn into wires.  It makes a squealing sounds when bent (like pure tin).

 Physical properties:

            Melting point: 429.75K=156.6 ºC

            Boiling point:  2345K=2072 ºC

            Superconduction point:  3.41K=-269.74 ºC

Pauling electronegativity: 1.78 Pauling units

Source:  Most Indium is found in the earth's crust.  It occurs predominantly found in sphalerite, a sulfide ore of iron.  45% of Indium comes from Canada, and another approximately 45% comes from China, Russia and France.  Japan is the world's leading consumer.

Price:  The present cost is about $1-$5 per gram depending on quantity and purity.      

Uses: 

            Indium is not a widely used element.  It can be used in making bearing alloys, germanium transistors, rectifiers, thermistors, and                     photoconductors

            It can also be used in mirrors that are as good as those made with silver, but are more resistant to atmospheric corrosion.

            It can be used in alloys with Gallium.

            It is also used in solders.

            Some thermal infrared cameras are made with indium.  See photo at the top. 

            There is research into how Indium can be used in LCDs and high definition televisions.  Because of these uses, the consumption of Indium is expected to increase dramatically in the next decade.