Details

Autor(en) / Beteiligte

• Liu, Junchang
• Mei, Yunhui
• Liu, Wen
• Li, Xin
• Hou, Feng
• Lu, Guo-Quan

Titel

Effects of sintering temperature on properties of toroid cores using NiZnCu ferrites for power applications at >1 MHz

Ist Teil von

• Journal of magnetism and magnetic materials, 2018-05, Vol.454, p.6-12

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

2018

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• [Display omitted] •The higher permeability could be obtained by increasing sintering temperature.•Higher permeability doesn’t mean better electrical performance due to its early reaching to magnetic flux saturation.•The core sintered at 950 °C has the lowest power loss density at both 5 mT and 10 mT under 1 MHz.•The core sintered at 950oC has the higher inductance at 1 MHz than that sintered at 1000oC. The microstructures, magnetic and electronic performance of NiZnCu ferrites have been investigated at temperature from 850 °C to 1000 °C. X-ray diffraction (XRD) patterns showed that only single phase with spinel structure existed. Scanning electron microscopy (SEM) results showed that grain size increased with enhancement of sintering temperature and the most homogeneous, compact microstructure was obtained at 950 °C. Magnetic properties measurements revealed that both complex permeability and saturation magnetization increased with increasing of sintering temperature. The initial permeability was approximately linear within the scope of 850–1000 °C as well as the resonance frequency decreased from 70 MHz to 30 MHz. Power loss density tests demonstrated that the core sintered at 950 °C instead of the one sintered at 1000 °C had the lower power loss density at both 5 mT and 10 mT and the higher inductance under a certain exciting direct current at 1 MHz. Also the inductance of the sample sintered at the higher temperature dropped faster than that at the lower temperature. The results showed that the core sintered at 950 °C had better electrical performance and was suitable for wide usage.