Influence of structural transformations on electric and magnetic properties of Fe81B13Si4C2 amorphous alloy

The structural transformations of the Fe81B13Si4C2 amorphous alloy under nonisothermal as well as under isothermal conditions were studied. The amorphous alloy was stable up to a temperature of about 450?C when the structural transformations began. The primary crystallization starts by forming Fe3Si as main phase (more than 80 wt %), and two minor phases Fe2B and Fe3B. With the increase of the temperature the phase composition as well as ratio of present phases is changed and above 600oC it was confirmed the presence only two stable phases, Fe3Si and Fe2B. It was shown that all observed structural transformations have significant influence on the electric and magnetic properties of alloy. The electric resistivity of the crystallized alloy is lower than the amorphous one. The crystallized alloy possesses better magnetic susceptibility and retains the ferromagnetic properties in whole investigated temperature range. Proucavane su strukturne transformacije Fe81B13Si4C2 amorfne legure u neizotermalnim kao i u izotermalnim uslovima. Pokazano je da je ispitivana amorfna legura stabilna do oko 450?C kada podleze nizu strukturnih transformacija. Primarna kristalizacija pocinje formiranjem Fe3Si kao najzastupljenije kristalne faze (more than 80 mas%) i dve manje zastupljene kristalne faze Fe2B i Fe3B. Sa porastom temperature menja se fazni sastav i maseni odnos prisutnih faza. Iznad 600oC potvrdjeno je samo prisustvo dve stabilne faze Fe3Si i Fe2B. Pokazano je da opazene strukturne transformacije imaju znacajan uticaj na elektricna i magnetna svojstva. Elektricna provodljivost kristalne legure je znatno niza. Medjutim kristalizacijom magnetna propustljivost raste i kristalna legura zadrzava feromagnetna svojstva u celom temperaturskom intervalu.