Magnetic Properties and Mössabauer Investigations of Fe-Ga Alloys

Abstract

The lattice parameters of the α-phase (disordered bcc), the metastable α''-phase (Fe 3 Al type) and the stable β-phase (Cu 3 Au type) in the Fe-Ga system containing 15∼30% Ga were determined and a phase diagram is proposed according to X-ray and magnetic measurements. The magnetic properties of these phases were investigated between 4.2 K and 1100 K. The magnetic moment per Fe atom was found to be 2.05±0.06µ B and 2.39±0.06µ B for the ordered bcc and the ordered fcc Fe 3 Ga respectively. Mössbauer measurements on the α'' and β phases were carried out and the internal fields were estimated to be 274 kOe for the fcc Fe 3 Ga and 230 and 360 kOe for the A and D sites respectively of the bcc Fe 3 Al-type Fe 3 Ga. Large quadrupole interactions were found in the fcc Fe 3 Ga and its spin direction is suggested to be along <100>. Some discussions are given in the last section.