gels期刊投稿

Journal of Alloys and CompoundsVolume 479, Issues 1-2, 24 June 2009, Pages 863-869--------------------------------------------------------------------------------doi:10.1016/j.jallcom.2009.01.081 | How to Cite or Link Using DOICopyright © 2009 Elsevier B.V. All rights reserved. Cited By in Scopus (0)Permissions & ReprintsSynthesis and magnetic properties of quasi-single domain M-type barium hexaferrite powders via sol–gel auto-combustion: Effects of pH and the ratio of citric acid to metal ions (CA/M)Liu Junlianga, Zhang Weia, Guo Cuijinga and Zeng Yanwei, a, ,aSchool of Materials Science and Engineering, Nanjing University of Technology, Nanjing 210009, PR ChinaReceived 4 July 2008; revised 20 January 2009; accepted 22 January 2009. Available online 4 February 2009.AbstractQuasi-single magnetic domain M-type barium hexaferrite powders have been synthesized via sol–gel auto-combustion route, followed by secondary heating treatment at 800 °C for 4 h, using barium nitrate, ferrite nitrate, ammonium nitrate, citric acid, and ammonia solution as the starting materials. The auto-combustion producing powders were γ-Fe2O3 and BaCO3 with aid of additional ammonium nitrate to increase the combustion temperature. The influences of the citric acid to metal ions (CA/M) and pH values on the gel auto-combustion, the phase compositions of the synthesized powders and their magnetic properties have been studied. The results showed that the chelation of barium and ferrite ions were important for the phase formation of barium hexaferrite: the phase compositions of the synthesized powders changed from a multi-phased mixture to a single phase of M-BaFe12O19 for the gradually complete complexing of barium and iron ions with citrate as the pH values and CA/M increased. The resulting powders demonstrated that various magnetic properties mainly depended on the variation in phase composition, sintering adhesion between grains and grown-up of crystalline sizes. With CA/M = 1.5, pH 7, the synthesized powders had a particle size distribution in the range of 100–200 nm and a saturation magnetization of 58.0 emu/g at 12 kOe.Keywords: Barium hexaferrite; Auto-combustion; Phase formation; Magnetic propertiesArticle Outline1. Introduction2. Experimental3. Results and discussions3.1. The complexing of metal ions with citric acid3.2. The combustion process of the dried gels3.3. The XRD patterns of combustion powders and resulting powders varied with pH values3.4. The XRD patterns of combustion powders and resulting powders varied with CA/M3.5. TEM analysis of the synthesized powders3.6. The magnetic properties of the resulting powders4. ConclusionsAcknowledgementsReferences文献来源：Academic Source Premier 数据库请留下有效邮箱，待采纳为正确答案后，即刻发送至指定邮箱。------------------------------我只是分割线-------------------------------文件已发送至指定邮箱。请查收@ jdxu1989附件包括：1、源网页文件:Effects of pH and the ratio of citric acid to metal ions (CAM).mht (724.96K)2、pdf电子文档：sdarticle.pdf (1.34M)3、word文档：Effects of pH and the ratio of citric acid to metal ions (CAM).doc (408.5K)