Low-temperature specific-heat study of Fe-rich Fe-Zr amorphous alloys

Low-temperature specific heats for Fe-rich Fe 100-x Zr x amorphous alloys with compositions of x=8, 9, 10 and 11 were measured in the temperature range between 1.5 and 6K. The total specific heat is found to follow the linear relation C= gamma T+ beta with a negative coefficient beta , in sharp contrast with the ordinary relation C= gamma T+ alpha T 3 . The linearly temperature-dependent coefficient is extremely high and well exceeds 20 mJ mol -1 K -2 . It increases further with decreasing Zr content. The large coefficient gamma can be ascribed to the sum of electronic and magnetic contributions. The magnetic specific heat can be expressed in the form A 0 +A 1 T+A 3 T 3 in the temperature range studied.