Osmium and Iridium - Comparison - Properties

This article contains comparison of key thermal and atomic properties of osmium and iridium, two comparable chemical elements from the periodic table. It also contains basic descriptions and applications of both elements. Osmium vs Iridium.

osmium and iridium - comparison

Compare osmium with another element

Compare iridium with another element

Osmium and Iridium – About Elements

Osmium

Osmium is a hard, brittle, bluish-white transition metal in the platinum group that is found as a trace element in alloys, mostly in platinum ores. Osmium is the densest naturally occurring element, with a density of 22.59 g/cm3. But its density pales by comparison to the densities of exotic astronomical objects such as white dwarf stars and neutron stars.

Iridium

Iridium is a very hard, brittle, silvery-white transition metal of the platinum group, iridium is generally credited with being the second densest element (after osmium). It is also the most corrosion-resistant metal, even at temperatures as high as 2000 °C.

Osmium in Periodic Table

Iridium in Periodic Table

Source: www.luciteria.com

Osmium and Iridium – Applications

Osmium

Due to its rarity and hence expense, osmium has only a few industrial uses. It is used to produce very hard alloys for fountain pen tips, instrument pivots, needles and electrical contacts. It is also used in the chemical industry as a catalyst. Finely divided osmium metal can be used as a catalyst e.g. in the process of forming ammonia by combining hydrogen and nitrogen.

Iridium

Iridium is mainly consumed by the automotive, electronic, and chemical industries. Iridium metal is employed when high corrosion resistance at high temperatures is needed, as in high-performance spark plugs, crucibles for recrystallization of semiconductors at high temperatures, and electrodes for the production of chlorine in the chloralkali process. The demand for iridium surged from 2.5 tonnes in 2009 to 10.4 tonnes in 2010, mostly because of electronics-related applications that saw a rise from 0.2 to 6 tonnes – iridium crucibles are commonly used for growing large high-quality single crystals, demand for which has increased sharply.

Osmium and Iridium – Comparison in Table

Element	Osmium	Iridium
Density	22.61 g/cm3	22.65 g/cm3
Ultimate Tensile Strength	1000 MPa	2000 MPa
Yield Strength	N/A	N/A
Young’s Modulus of Elasticity	N/A	528 GPa
Mohs Scale	7	6.25
Brinell Hardness	3900 MPa	1670 MPa
Vickers Hardness	4140 MPa	1760 MPa
Melting Point	3045 °C	2410 °C
Boiling Point	5030 °C	4130 °C
Thermal Conductivity	88 W/mK	150 W/mK
Thermal Expansion Coefficient	5.1 µm/mK	6.4 µm/mK
Specific Heat	0.13 J/g K	0.13 J/g K
Heat of Fusion	31.8 kJ/mol	26.1 kJ/mol
Heat of Vaporization	746 kJ/mol	604 kJ/mol