Ultra-soft magnetic properties and correlated phase analysis by {sup 57}Fe Mössbauer spectroscopy of Fe{sub 74}Cu{sub 0.8}Nb{sub 2.7}Si{sub 15.5}B{sub 7} alloy

• Published in: AIP advances Vol. 6; no. 2
• Main Authors: Manjura Hoque, S., Liba, S. I., Akhter, Shireen, Anirban, A., Choudhury, Shamima
• Format: Journal Article
• Language: English
• Published: United States 15.02.2016
• Subjects: ABSORPTION SPECTROSCOPY; ANNEALING; BCC LATTICES; CALORIMETRY; CHEMICAL SHIFT; COERCIVE FORCE; CRYSTALLIZATION; GRAIN SIZE; IRON 57; IRON BASE ALLOYS; MAGNETIC PROPERTIES; MAGNETIZATION; MATERIALS SCIENCE; MOESSBAUER EFFECT; NANOSTRUCTURES; PHASE STUDIES; SILICON ALLOYS; SOLIDIFICATION; TRANSMISSION ELECTRON MICROSCOPY; VIBRATING SAMPLE MAGNETOMETERS; X-RAY DIFFRACTION
• ISSN: 2158-3226; 2158-3226
• DOI: 10.1063/1.4941838

A detailed study of magnetic softness has been performed on FINEMENT type of ribbons by investigating the BH loop with maximum applied field of 960 A/m. The ribbon with the composition of Fe{sub 74}Cu{sub 0.8}Nb{sub 2.7}Si{sub 15.5}B{sub 7} was synthesized by rapid solidification technique and the compositions volume fraction was controlled by changing the annealing condition. Detail phase analysis was performed through X-ray diffraction (XRD), Differential scanning calorimetry (DSC), Vibrating sample magnetometer (VSM) and Mössbauer spectroscopy in order to correlate the ultrasoft magnetic properties with the volume fraction of amorphous and α-Fe(Si) soft nano composites. Bright (BF) and dark field (DF) image with selective area diffraction (SAD) patterns by the transmission electron microscopy (TEM) of the sample annealed for the optimized annealed condition at 853 K for 3 min reveals nanocrystals with an average size between 10-15 nm possessing the bcc structure which matches with the grain size revealed by the X-ray diffraction. Kinetics of crystallization of α-Fe(Si) phases has been determined by DSC curves. Extremely small coercivity of 30.9 A/m and core loss of 2.5 W/Kg for the sample annealed at 853 K for 3 min was found. Similar values for other crystalline conditions were determined by using BH loop tracer with a maximum applied field of around 960 A/m. Mössbauer spectroscopy was used to determine chemical shift, hyperfine field distribution (HFD), and peak width of different phases. The volume fractions of the relative amount of amorphous and crystalline phases are also determined by Mössbauer spectroscopy. High saturation magnetization along with ultrasoft magnetic properties exhibits very high potentials technological applications.