Bismanol

Bismanol is a magnetic alloy of bismuth and manganese (manganese bismuthide) developed by the US Naval Ordnance Laboratory.

Bismanol

Identifiers
CAS Number	12010-50-3 Y
3D model (JSmol)	Interactive image
ChemSpider	20137871
EC Number	234-556-2
PubChem CID	6336867
CompTox Dashboard (EPA)	DTXSID8065161
InChI InChI=1S/Bi.Mn Key: KYAZRUPZRJALEP-UHFFFAOYSA-N
SMILES [Mn].[Bi]
Properties
Chemical formula	BiMn
Molar mass	263.91844 g·mol−1
Structure
Crystal structure	NiAs type
Space group	R3m[1]
Properties
Melting point	262 °C [2] Decomposes at ~335 °C (peritectic formation of MnBi)[2]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

History

Bismanol, a permanent magnet made from powder metallurgy of manganese bismuthide, was developed by the US Naval Ordnance Laboratory in the early 1950s – at the time of invention it was one of the highest coercive force permanent magnets available, at 3000 oersteds.^[3] Coercive force reached 3650 oersteds and magnetic flux density 4800 by the mid 1950s. The material was generally strong, and stable to shock and vibration, but had a tendency to chip. Slow corrosion of the material occurred under normal conditions.^[4]

The material was used to make permanent magnets for use in small electric motors.^[5]

Bismanol magnets have been replaced by neodymium magnets which are both cheaper and superior in other ways, by samarium-cobalt magnets in more critical applications, and by alnico magnets.^{[citation needed]}