TitleCo_xTi_(1-x)O_(2-δ)体材中氢退火引起的铁磁性及结构相变
Other TitlesRoom-temperature ferromagnetism in bulk CoxTi1-xO2-delta induced by the phase transformation in the hydrogenation sintering process
Authors孔令刚
康晋锋
王漪
刘力锋
刘晓彦
张兴
韩汝琦
Affiliation北京大学微电子学研究所
北京大学微电子学研究所 北京100871
Keywords室温铁磁性
结构相变
锐钛矿
氢退火
room-temperature ferromagnetism
phase transformation
anatase
hydrogenation
Issue Date2006
Publisher物理学报
Citation物理学报.2006,(03),1453-1457.
Abstract利用固相反应法在700℃—1000℃不同的温度下、空气中烧结Co3O4和TiO2混合物,制备了(Co_3O_4)_x/3(TiO_2)_(1-x)(0<x≤0·1)样品,所有的烧结样品均表现出顺磁行为,但经500℃氢退火后均表现出室温铁磁性.X射线衍射(XRD)分析显示,在所有样品中均存在钙钛矿相CoTiO3,说明Co3O4与TiO2反应形成了CoTiO3;同时,在700℃低温和900℃以上的高温烧结样品中分别观察到了单相的锐钛矿和金红石相结构.经高低温烧结的样品在500℃氢退火后,CoTiO3相消失,锐钛矿相的Co_xTi_(1-x)O_(2-δ)形成.X射线光电子能谱(XPS)分析显示,氢...
Paramagnetic (CO3 O-i TiO2)(1-x) (0 < x <= 0.1) samples were fabricated by sintering Co3O4 and TiO2 from 700 degrees C to 1000 degrees C in air. X-ray diffraction (XRD) results showed that perovskite CoTiO3 existed in all samples. Anatase phase was also detected in samples sinterod at 700 degrees C and when sintering the mixture at above 900 degrees C, rutile phase formed with anatase phase disappearing. All samples exhibited room-temperature ferromagnetism (RTFM) after being hydrogenated in 10% H-2/Ar mixed atmosphere for 1 hour at 500 degrees C. X-ray photoelectron spectroscopy (XPS) showed that Co existed in the + 2 formal oxidation state, and no Co clusters were detected. XRD showed that CoTiO3 disappeared and a new phase CoxT1-x O2-delta formed after hydrogenation. It is suggested that hydrogenation causes the phase transformation from CoTiO3 to Co(x)Ti1-O2-delta. RTFM of the sample originates from the intrinsic ferromagnetism of CoxTi1-xO2-delta. The exchange interaction between Co2+ occurring with the phase transformation may e the essential reason for RTFM.
URIhttp://hdl.handle.net/20.500.11897/22432
ISSN1000-3290
DOI10.3321/j.issn:1000-3290.2006.03.077
IndexedSCI(E)
中文核心期刊要目总览(PKU)
中国科技核心期刊(ISTIC)
中国科学引文数据库(CSCD)
Appears in Collections:信息科学技术学院

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