Structural studies of secondary crystallization products of the Fe23B6-type in a nanocrystalline FeCoB-based alloy

Abstract

A stable Fe 23 B 6-type phase formed in a nanocomposite soft magnetic alloy Fe 40 Co 40 Nb 4 B 13 Ge 2 Cu 1 after thermal treatment was investigated. The primary crystallization temperature and second crystallization temperature for this alloy were determined to be 405 and 740°C, respectively. After annealing the sample at 820°C for 1 h, a Fe 23 B 6-type phase ͑FeCoNb͒ 23 B 6 was observed. The structural information was investigated by x-ray diffraction, transmission electron microscopy, and three-dimensional atom probe. The Fe 23 B 6-type phase contains about 33± 5 at. % Fe, 38± 5 at. % Co, 7 ± 1 at. % Nb, and 20± 3 at. % B. The Nb atoms tend to occupy the 8c sites and Co/ Fe atoms occupy the 4a, 32f, and 48h sites of the Fm3m space group for this structure.

Increased induction in FeCo-based nanocomposite materials with reduced early transition metal growth inhibitors

“…8,9 From this family of materials, an alloy commercialized under the designation HTX-002 was selected for use in an inductor for a future hybrid ground vehicle 25 kW dc-dc prototype converter. 1 This paper presents the compositional modifications of this nanocomposite alloy, aimed at further increasing the induction by reducing amounts of the nonmagnetic growth inhibitors in the alloy.…”

The influence of pressure on the phase stability of nanocomposite Fe89Zr7B4 during heating from energy dispersive x-ray diffraction

“…12,13 Soft magnetic performance degrades significantly following secondary crystallization and accurate prediction of this phenomenon is important for aging studies of nanocomposites.…”

“…Evidence of these phases has been found previously in FeCo based nanocomposites. 12,13 Due to the instrument broadening, the amount of secondary crystallization was estimated by integrating a peak centered at 39 keV, which corresponds to the Fe 23 B 6 (115) peak. In the 0.5 GPa experiment, this peak area decreases at 710 C due to a shift in the neighboring peaks.…”

Thermal induced structural and magnetic transformations in Fe73.5−xCex=0,3,5,7Si13.5B9Nb3Cu1 amorphous alloy

“…So far, many different modifications of the basic FeSiB composition were analysed while searching for better technical properties [4][5][6][7][8][9][10]. The analysis was focused rather on products of primary crystallization at lower annealing temperatures with less interest on the secondary crystallization.…”