Title :
Nanocrystalline Nd6Fe88-xMxB6 (M=Ti or V) magnets by rapid thermal annealing
Author :
Fang, J.S. ; Chin, T.S. ; Chen, S.K.
Author_Institution :
Dept. of Mater. Sci. & Eng., Tsinghua Univ., Beijing, China
fDate :
9/1/1996 12:00:00 AM
Abstract :
Nanocrystalline structures were obtained by a rapid thermal annealing (RTA) process with a heating rate of 600°C/min for a soaking time of 2 minutes for melt-spun Nd6Fe88-xMxB6 amorphous alloys (M=Ti or V, x=0~5), Exchange coupling interaction between the magnetically hard and soft phases was studied with the δM plots. Addition of Ti or V to replace iron is effective in increasing remanence ratio, Mr/M2T , and energy product of the modified alloys, especially that modified by V, although both saturation magnetization and remanence are decreased due to magnetic dilution. High resolution TEM studies showed that both Ti and V is effective in refining grain size of both hard and soft phases to 20-23 nm compared with 50~52 nm for the z=0 alloy. The substitution with V results in a decrease in coercivity despite of refined grains
Keywords :
boron alloys; coercive force; exchange interactions (electron); ferromagnetic materials; grain size; iron alloys; magnetic particles; melt spinning; neodymium alloys; permanent magnets; rapid thermal annealing; remanence; soft magnetic materials; titanium alloys; transmission electron microscopy; vanadium alloys; 2 min; 20 to 23 nm; 50 to 52 nm; Nd6Fe88-xTixB6; Nd6Fe88-xVxB6; Nd6Fe88TiB6; Nd6Fe88VB6; TEM; coercivity; exchange coupling interaction; grain size; heating rate; magnetic dilution; magnetically hard phase; magnetically soft phase; nanocrystalline structures; rapid thermal annealing; remanence ratio; saturation magnetization; soaking time; substitution; Amorphous magnetic materials; Heating; Iron alloys; Nanostructures; Neodymium; Rapid thermal annealing; Rapid thermal processing; Remanence; Saturation magnetization; Titanium alloys;
Journal_Title :
Magnetics, IEEE Transactions on
