Title :
Effects of B and Mo on the magnetic properties of NdFeTi-nitrides with ThMn12-type structure
Author :
Kim, Yoon B. ; Kim, Hee T. ; Kim, Chang S. ; Kim, Taik K.
Author_Institution :
Magnetics Lab., Korea Res. Inst. of Stand. & Sci., Taejon, South Korea
fDate :
11/1/1993 12:00:00 AM
Abstract :
Alloys having a nearly single phase of ThMn12-type structure (1-12 phase) are successfully synthesized in NdFe10.7 Ti1.3-yMy (M=B/Mo) alloy systems by substituting B or Mo up to 23% of Ti (y=0.3). After nitrification, the unit cell volume of 1-12 phase increases by about 2-3% and α-Fe phase of 5-15 wt.% is formed, depending on the substitutional elements. The nitrides, NdFe10.7TiB0.3 Nx and NdFe10.7TiMo0.3Nx , are confirmed to have uniaxial anisotropy by X-ray diffractometry. The results of magnetic measurements for the nitrides show that B is very effective for the increase of both Curie temperature and magnetization. On the other hand, Mo is effective for the increase of anisotropy field, but it decreases the magnetization. The Curie temperature and magnetization of NdFe10.7TiB0.3N x are 560°C and 148 Am2/kg, respectively, about 20% and 15% higher than those of NdFe10.7Ti1.3 Nx. The anisotropy field of NdFe10.7TiMo is about 7960 kA/m (100 kOe), which is about 25% higher than that of NdFe 10.7Ti1.3Nx
Keywords :
Curie temperature; X-ray diffraction examination of materials; boron alloys; crystal atomic structure of alloys; ferromagnetic properties of substances; iron alloys; magnetic anisotropy; magnetisation; molybdenum alloys; neodymium alloys; nitridation; permanent magnets; titanium alloys; α-Fe phase; 560 degC; Curie temperature; NdFe10.7TiB0.3Nx; NdFe10.7TiMo0.3Nx; NdFeTi-nitrides; NdFeTiB; NdFeTiMo; ThMn12-type structure; X-ray diffractometry; anisotropy field; magnetic properties; magnetization; nearly single phase; nitrification; uniaxial anisotropy; unit cell volume; Anisotropic magnetoresistance; Magnetic field measurement; Magnetic materials; Magnetic properties; Magnetic variables measurement; Magnetization; Neodymium; Powders; Titanium alloys; X-ray diffraction;
Journal_Title :
Magnetics, IEEE Transactions on
