2006 Volume 47 Issue 6 Pages 1568-1571
The amorphous formation ability and the magnetic properties of Nd60Fe30−xCoxAl10 (x=10, 15, 20 or 30) alloys in the containerless process were studied by the new gas jet flow type levitating process. The gas jet flow type levitating process enables solidification without any container wall by the inert gas jet. The samples were solidified at the cooling rate of around 100 K/s. Then, the undercooling of samples exhibits high values (ΔT=60–150 K). From X-ray diffraction measurements, the Nd60Fe30−xCoxAl10 samples exhibit a typical broad diffraction pattern for an amorphous structure. The DTA curves of x=10, 15 and 20 showed an exothermic peak due to the crystallization. That is, it was revealed that the Nd60Fe30−xCoxAl10 samples formed bulk amorphous. Also, the coercivity is 1.6, 3.3 and 3.6 kOe for the Nd60Fe20Co10Al10, Nd60Fe15Co15Al10 and Nd60Fe10Co20Al10, respectively. From the thermomagnetic curves, the Curie temperature is determined to be 463, 482 and 482 K for the Nd60Fe20Co10Al10, Nd60Fe15Co15Al10 and Nd60Fe10Co20Al10, respectively. In the M-H loops and the thermomagnetic curves, this difference between x=10 and x=15, 20 may depend on the microstructure.