Rapidly quenched Fe_xTa_100-x alloys

Authors

• C.L. Chien, Johns Hopkins University, Baltimore, Maryland
• Sy_Hwang Liou, University of Nebraska-LincolnFollow
• B.K. Ha, Johns Hopkins University, Baltimore, Maryland
• K.M. Unruh, Johns Hopkins University, Baltimore, Maryland

Document Type

Article

Date of this Version

April 1985

Comments

Published by American Institute of Physics. J. Appl. Phys. 57, 3539 (1985). ©1985 American Institute of Physics. Permission to use. Journal home page = http://jap.aip.org/jap/.

Abstract

Binary alloys of Fe_xTa_100-x were made by high-rate sputtering. A sharply defined boundary separates the composition ranges in which crystalline alloys (93 ≤ x ≤100) and amorphous alloys (15 ≤ x ≤ 90) are formed. The amorphous alloys with Fe concentrations up to the threshold of x_c ≈ 65 are nonmagnetic. For the samples with x > x_c, the magnetic ordering temperature (T_c) varies monotonically with Fe content to 200 K for a-Fe₉₀Ta₁₀. However, the crystalline alloys, with slightly higher Fe content, are strongly ferromagnetic. Their T_c's are several hundred degrees higher, accompanied by large increases in magnetic moment and hyperfine fields. This discontinuity illustrates the sensitivity with which the magnetic properties of Fe-transition metal alloys depend on structure. In contrast, no discontinuity has been observed in Co-Ta alloys.