Iron diboride, FeB2, has been prepared in a similar manner to the sub-boride, and represents the maximum limit of combination of iron with boron. Its density is 5; it is slightly yellow in colour, hard, and friable, being readily oxidised by moist air.
Other complexes, such as Fe5B6, Fe3B4, Fe2B3, have been prepared, but are probablv not all separate chemical entities. |