Title :
Magnetic properties and microstructure of melt-spun Nd-Fe-Ga-B alloys
Author :
Panagiotopoulos ; Murthy, A.S. ; Hagjipanayis, G.C.
Author_Institution :
Dept. of Phys. & Astron., Delaware Univ., Newark, DE, USA
fDate :
11/1/1995 12:00:00 AM
Abstract :
The magnetic and microstructural properties of melt-spun Nd18 Fe76-xGaxB6 alloys have been studied as a function of Ga content. Coercivities of 17 kOe were obtained in underquenched samples having a large grain size of 500 nm. Samples prepared at wheel speeds of 15-19 m/sec, as well as overquenched (40 m/sec) and subsequently annealed, gave coercivities of around 20 kOe with no significant improvement of Hc upon Ga substitution. In Ga-free samples prepared by annealing highly overquenched ribbons (at 60 m/sec) only moderate coercive fields could be achieved (14 kOe). These samples had grain sizes of 70-100 nm. However Ga substituted samples prepared under the same conditions have a fine grain structure consisting of unequiaxed grains with size around 20 nm and show coercivities up to 23 kOe
Keywords :
annealing; boron alloys; coercive force; ferromagnetic materials; gallium alloys; grain size; iron alloys; magnetic hysteresis; neodymium alloys; permanent magnets; quenching (thermal); 20 nm; 500 nm; 70 to 100 nm; Ga content; Ga-free samples; Nd18(FeGa)76B6; Nd18Fe76-xGaXB6 alloys; annealing; coercivities; fine grain structure; highly overquenched ribbons; large grain size; magnetic properties; melt-spun Nd-Fe-Ga-B alloys; microstructure; underquenched samples; unequiaxed grains; Annealing; Coercive force; Gallium alloys; Grain size; Magnetic domain walls; Magnetic hysteresis; Magnetic properties; Magnets; Microstructure; Wheels;
Journal_Title :
Magnetics, IEEE Transactions on
