Department of Mechanical Engineering, National Cheng Kung University, Tainan, Taiwan
Material Research Laboratory, I.T.R.I., Nantzu, Kaoshiung, Taiwan
Abstract:
The anisotropy properties of samarium-Alnico V pseudobinary alloys have been investigated. With alloys containing less than 12.0 mol% samarium, the K1 values are negative at 77 K and increase with increasing temperature to approximately zero at room temperature. The K2 values remain positive at all temperatures. We do not find the easy cone that has long been thought to be existed in those alloys with K1 < 0 and K2 #62; 0. In alloys with samarium contents between 13.3 and 19.0 mol%, the K1 and K2 values are positive at all temperatures. The anisotropy fields are not changed monotonically in the whole range of 10.1 to 19.0 mol% of samarium. It is concluded that the alloys are characteristics in thermodynamically of first-order transition. We have found that the “hard cone” exists in each of those alloys with samarium content more than 16.0 mol% and at temperatures above 77 K. The alloys with samarium less that 13.4 mol% also have “hard cone” under 77 K. However, the observed “hard cone” is different from the well known one in the first-order magnetization process, and it will collapse to the easy axis when the measuring field and temperature increase while under room temperature.