MAGNETIC-PROPERTIES OF GDMNXFE1-XSI INTERMETALLIC COMPOUNDS

Magnetic properties of GdMnxFe1-xSi (x = 1, 0.9, 0.8, 0.7, 0.6, 0) com pounds were investigated. Both GdMnSi and GdFeSi crystallize in the Ce FeSi-type tetragonal structure and form a complete solid solution with out any change in the crystal structure. Magnetic measurements were ma de in static magnetic fields up to 1 MA/m in the temperature range fro m 77 K to 420 K. For GdFeSi these measurements were carried out on sin gle crystal sample. It was found that the increase in Fe content leads to a sharp decrease in saturation magnetic moment. The Curie temperat ure increases in the concentration range 0.7 less than or equal to x l ess than or equal to 1 and monotonously decreases for x less than or e qual to 0.6. These effects could be explained by strong dependence of the exchange integrals on the interatomic distances.