Spark-plasma-sintering magnetic field assisted compaction of Co80Ni20 nanowires for anisotropic ferromagnetic bulk materials

作者：Ouar Nassima; Schoenstein Frederic^*; Mercone Silvana; Farhat Samir; Villeroy Benjamin; Leridon Brigitte; Jouini Noureddine

来源：Journal of Applied Physics, 2013, 114(16): 163907.

DOI：10.1063/1.4827199

We developed a two-step process showing the way for sintering anisotropic nanostructured bulk ferromagnetic materials. A new reactor has been optimized allowing the synthesis of several grams per batch of nanopowders via a polyol soft chemistry route. The feasibility of the scale-up has been successfully demonstrated for Co80Ni20 nanowires and a massic yield of similar to 97% was obtained. The thus obtained nanowires show an average diameter of similar to 6 nm and a length of similar to 0 nm. A new bottom-up strategy allowed us to compact the powder into a bulk nanostructured system. We used a spark-plasma-sintering technique under uniaxial compression and low temperature assisted by a permanent magnetic field of 1 T. A macroscopic pellet of partially aligned nanowire arrays has been easily obtained. This showed optimized coercive properties along the direction of the magnetic field applied during compaction (i.e., the nanowires%26apos; direction).

• 出版日期2013-10-28