Abstract
The effect of Co addition on the magnetic properties and microstructure for the nanocrystalline Fe93-xNb2(Nd,Pr)2B2 (x = 5-7) alloys produced by crystallization of an amorphous phase has been investigated. The melt-spun Fe93-x-yCoxNb2(Nd,Pr)y B5 (x = 0-20 and y = 5-7 at.%) ribbons form a nanocomposite structure of bcc-(Fe,Co) and Pr2(Fe,Co)14B with grain sizes of 10-50 nm after annealing at 973-1023 K, showing a smooth J-H curve typical for the exchange-spring magnet. The alloys containing Co show a high energy product ((BH)max) upon annealing at a relatively low temperature presumably because the precipitation temperature of each phase decreases by addition of CO. The (BH)max values after annealing at an optimum temperature are improved by addition of 5-20 at.% Co for the Fe86-xCoxNb2(Nd,Pr)7B5 and Fe88-xCoxNb2Nd5B5 alloys. The improvement of (BH)max by Co addition is attributed to the enhancement of Jr, presumably resulting from the increase in magnetization of each phase and the exchange-coupled region between the soft and hard magnetic phases.
| Original language | English |
|---|---|
| Pages (from-to) | 1383-1387 |
| Number of pages | 5 |
| Journal | Scripta Materialia |
| Volume | 44 |
| Issue number | 8-9 |
| DOIs | |
| Publication status | Published - 2001 May 18 |
| Externally published | Yes |
Keywords
- Amorphous
- Crystallization
- Magnetic properties
- Nanocomposite magnet
- Remanence enhancement
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys