Features of Electron Beam Processing of Mn-Zn Ferrites in the Fore-Vacuum Pressure Range in Continuous and Pulse Modes

Abstract

The results of electron beam processing of Mn-Zn ferrite samples using pulsed and continuous electron beams in the fore-vacuum pressure range (10 Pa) are presented. We find that continuous electron beam processing leads to surface structuring of the ferrite, changes in elemental composition on the surface, and electrical property modification. The degree of ferrite parameter changes exhibits a threshold behavior. For surface processing temperatures below 900 °C, changes are barely noticeable, while for temperatures over 1100 °C the surface resistance decreases by more than an order of magnitude to values of less than 3 kOhm. Electron beam processing with millisecond pulse duration and pulse energy density exceeding 15 J/cm2 results in the formation of low zinc content melt islands, while the remaining surface area (outside the islands) elemental content and ferrite properties remain largely unchanged. The thickness of the modified layer depends on the processing mode and can be controlled over the range of 0.1–0.5 mm. Due to its low resistance, the modified layer can be utilized to enhance the RF-absorbing properties of the ferrite, which is important in the design of modern magnetic elements of electronic equipment.