Nanocrystalline soft magnetic ribbon with α″-Fe16N2 nanocrystallites embedded in amorphous matrix

Iron Nitride Family at Reduced Dimensions: A Review of Their Synthesis Protocols and Structural and Magnetic Properties

“…In general, the overall M S will decrease if the samples contain additional phases with lower magnetization than α″-Fe 16 N 2 , and the individual M S values can be estimated if the volume fraction of each component is known. 124 In the 20 nm particles, the RT coercivity (H C ) was 3350 Oe which increased rapidly below 25 K. The presence of a magnetically ordered oxide shell has the advantage of pinning the core FM spins at the core/ shell interface and demonstrating the presence of exchange anisotropy through a shift of the hysteresis loop along the field axis. In this case, a hysteresis loop shift of 200 Oe was observed at 5 K. The magnetic uniaxial anisotropy was found to be 4.4 × 10 6 erg/cm 3 from the magnetic torque measurement under 2.2 T field following the coherent rotation model.…”

“…The method of reducing the Fe-oxides in H 2 at 250–600 °C for 3–5 h and subsequent nitriding the Fe NPs in NH 3 or NH 3 + H 2 (g) mixture at 100–200 °C had been used to make ∼20 nm α″-Fe 16 N 2 NPs with a thinner oxide coating. , The surface of the α″-Fe 16 N 2 NPs could be coated with Y or Al compounds to protect the NPs from oxidation and sintering . α″-Fe 16 N 2 nanocrystallites embedded in an amorphous Fe 92 B 8 matrix were obtained by annealing the amorphous ribbon in 92:8 NH 3 :H 2 at 600 °C for 45 min, homogenizing in Ar for 30 min, quenching in water, and tempering at 150 °C for 2 h . The nitrogen content of the amorphous matrix was found to be 7.8 atomic %.…”

“…Because of the presence of this amorphous oxide layer, the overall M S was 108 emu/g, and that of the FM core part was 196 emu/g Fe . In general, the overall M S will decrease if the samples contain additional phases with lower magnetization than α″-Fe 16 N 2 , and the individual M S values can be estimated if the volume fraction of each component is known . In the 20 nm particles, the RT coercivity ( H C ) was 3350 Oe which increased rapidly below 25 K. The presence of a magnetically ordered oxide shell has the advantage of pinning the core FM spins at the core/shell interface and demonstrating the presence of exchange anisotropy through a shift of the hysteresis loop along the field axis.…”

“…α″-Fe 16 N 2 nanocrystallites embedded in an amorphous Fe 92 B 8 matrix were obtained by annealing the amorphous ribbon in 92:8 NH 3 :H 2 at 600 °C for 45 min, homogenizing in Ar for 30 min, quenching in water, and tempering at 150 °C for 2 h 124. The The Journal of Physical Chemistry C…”