ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Magnetically hard Sm5(Fe,Co,Ti)17 phases have been synthesized by the conventional powder metallurgical method. A representative magnet of composition Sm5(Fe0.94Ti0.06)17 shows a room-temperature coercivity, iHc, ∼21.5 kOe, remanence, Br, ∼3.5 kG, and Curie temperature, Tc∼300 °C. The main phase of the magnets has the hexagonal Nd5Fe17 structure with a=20.146 A(ring), c=12.310 A(ring). The magnets contained minor amounts of Sm2(Fe,Ti)17 and Sm(Fe,Ti)3, as detected by thermomagnetic analyses (TMA). When Fe is partially substituted by Co, Tc increases, by ∼40 °C for the magnet of composition Sm5(Fe0.74Co0.20Ti0.06)17. This magnet exhibits iHc∼4.0 kOe and Br∼3.4 kG at room temperature. It consists of 2:17, 5:17, and 1:2 phases. The effects of heat treatment procedure on the phase formation and magnetic properties of the magnets have been studied. The best sintering temperature for forming the 5:17 phase, as well as for developing the highest iHc, is ∼700–850 °C. Above 850–1000 °C the 2:17 and 1:2 or 1:3 phases become dominant, the 5:17 hard phase almost disappears, and the coercivity of the magnets decreases substantially.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.353516
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