CF4 plasma treatment on germanium (Ge) surface is proposed in this work to alleviate the strong Fermi level pinning between metal/Ge, and its effectiveness is also explored for n- and p-type Ge wafers. It is found that samples with CF4 plasma treatment reveal conduction behavior transition between Schottky and ohmic characteristics, a metal-work-function-dependent Schottky barrier height as well as modulated contact resistance, and these results confirm the depinning of Fermi level. This depinning can be explained by the effective capability in passivating dangling bonds at Ge surface through fluorine atoms and the formation of Ge-F binding with partial ionic property, both of which are helpful in decreasing the number of surface states and consequently release the pinning effect.
The effects of cerium content in the range of 0-0.022 wt%, on the microstructure, texture and magnetic properties of four non-oriented electrical steels have been studied. After final annealing, grain size increased with increasing cerium content and reached a maximum value in the steel with 0.011 wt% cerium. Furthermore, steel containing 0.003 wt% cerium had the strongest (110)͗001͘ texture among the steels. In the steel with the same cerium content, the intensity of (111)͗uvw͘ fiber texture decreased with decreasing hot finishing rolling temperature and increasing hot band annealing temperature. Under the same processing conditions, flux density slightly increased with increasing cerium and reached a maximum value in the steel with 0.003 wt% cerium. For steel with the same cerium content, flux density increased with increasing hot band annealing temperature and decreasing hot finishing rolling temperature. Conversely, core loss decreased with increasing cerium content and reached a minimum value in the steels containing 0.003 wt% cerium. For steel with the same cerium content, core loss decreased with increasing hot band annealing temperature and decreasing hot finishing rolling temperature. Steel with 0.003 wt% cerium obtained the best magnetic properties, predominantly through the development of favorable texture and optimum grain size.KEY WORDS: electrical steel; cerium; texture; grain size; magnetic property.nace and cast into 500 mmϫ300 mmϫ100 mm ingots. Table 1 shows their chemical compositions. The proportions of cerium content were 0, 0.003, 0.011, and 0.022 wt%. The proportions of other elements were 0.003 wt% carbon, 1.15 wt% silicon, 0.42 wt% manganese, 0.009 wt% phosphorus, 0.006 wt% sulfur, and 0.33 wt% aluminum, with 0.002 wt% nitrogen and 0.0007 wt% oxygen. The steel ingots were reheated to 1 200°C for 2 h, and hot-rolled in two steps by a two-high pilot hot rolling mill with intermediate annealing at 1 200°C for 1 h. Two levels of hot-rolled finishing temperature were conducted at 890°C and 820°C. The thickness of steel ingots after rough rolling was 20 mm, and after finishing rolling was 3.2 mm. After air cooling to room temperature, hot-rolled bands were annealed at 900°C and 700°C respectively for 2 h and allowed to cool in the furnace. Then, the annealed hot-rolled bands were uniformly milled to 2.3 mm by a milling machine from both sides to remove any scale on the surfaces. A four high pilot cold rolling mill was used to cold-roll the hot-rolled bands to the final thickness of 0.5 mm with a total reduction of 78 %. Then, the cold-rolled steels sheets were cut into 60 mmϫ30 mm coupons both in longitudinal and transverse direction with respect to the rolling direction. Finally, the coupons were annealed in a vacuum infrared furnace set at 950°C for 2 min with a heating rate 5°C per second to simulate continuous annealing.After cold-rolling and final annealing, magnetic properties of the specimens were measured using a Soken DAC-BHW-2 electrical steel tester. Magnetic flux density was measure...
The effect of hot band annealing temperature, range from 700-1 OOO'C, on the magnetic properties of low-carbon electrical steels measuredat 10
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.