Magnetic and structural properties of the Fe5Si1-xGexB2 system

A series of compounds with compositions Fe5Si1-xGexB2 were synthesised and their structural and magnetic properties were investigated. The Mo5SiB2-type structure with tetragonal I4/mcm space group is maintained for all compounds with x < 0.15, which is estimated as the compositional limit of the system. The unit cell pa-rameters expand with Ge content before reaching a plateau of a = 5.5581(1) and c = 10.3545(1) angstrom at x = 0.15. The saturation magnetisation (MS) decreased slightly with increasing Ge content whilst the magnetocrystalline anisotropy energy (MAE) remains almost unaffected. The Curie temperature for all compounds studied is at 790 K whilst the spin-reorientation temperature shows suppression from 172 K to 101 K where x = 0.15. Ab Initio calculations reveal an increase in MAE for compositions up to x = 0.25 and a decreased magnitude of MAE of-0.14 MJ/m3 for the hypothetical compound Fe5GeB2 relative to the parent compound Fe5SiB2.

Automated summary

A series of Fe5Si1-xGexB2 compounds were synthesized and their structural and magnetic properties were investigated. The compounds maintained the Mo5SiB2-type structure with Ge content below 0.15, and the unit cell parameters expanded as Ge content increased. The saturation magnetisation decreased slightly with increasing Ge content, while the magnetocrystalline anisotropy energy remained almost unchanged. The Curie temperature for all compounds studied was 790K, and the spin-reorientation temperature decreased from 172K to 101K at x = 0.15.