Fabrication of 0-3 type manganite/insulator composites and manipulation of their magnetotransport properties

doi:10.1063/1.3262624

CORC > 兰州理工大学 > 兰州理工大学 > 省部共建有色金属先进加工与再利用国家重点实验室

	Fabrication of 0-3 type manganite/insulator composites and manipulation of their magnetotransport properties
	Yang, H.1,2; Cao, Z. E.1; Shen, X.1; Xian, T.1; Feng, W. J.1; Jiang, J. L.1; Feng, Y. C.1; Wei, Z. Q.1; Dai, J. F.1
刊名	JOURNAL OF APPLIED PHYSICS
	2009-11-15
卷号	106 期号:10
关键词	Enhanced magnetoresistance Fabrication Lanthanum compounds Magnesia Manganese oxide Manganites Metal insulator boundaries Particle size Perovskite Powder metals Semiconductor insulator boundaries Shells (structures) Structural properties Temperature Tensile strain
ISSN号	0021-8979
DOI	10.1063/1.3262624
英文摘要	In order to promote the technological applications of perovskite manganites, a great fundamental interest has been devoted to tailoring and/or enhancing their magnetotransport properties. Design and fabrication of manganite-based nanocomposites offer great potential to tailor the magnetotransport properties. In this work, we illustrate the promising concept of 0-3 type manganite/insulator composites (where manganite nanoparticles are uniformly and discretely embedded in a three-dimensional-connectivity insulator matrix) through the example of the La0.67Ca0.33MnO3 (LCMO)/MgO system. We present a promising strategy, which is based on the creation of core (LCMO)-shell (MgO) composite powders, for the synthesis of 0-3 type LCMO/MgO composites. A modified polyacrylamide gel method has been developed to prepare the core-shell structured LCMO/MgO composite powders. Besides its ability to create well-defined core-shell composite structures, the present gel method also allows the production of nanopowders with uniform particle size and in spherical shape. In our (1-x)LCMO/xMgO composite system, the lattice of LCMO is found to expand with rising MgO concentration x, yielding a bulk tensile strain. The increase in the tensile strain with x yields to a structural phase transition in the LCMO phase from an orthorhombic Pnma structure (x <= 0.2) to a rhombohedral R (3) over barc structure (x >= 0.3), and this structural transition leads to a relaxation of the strain. The strain effects induced by the MgO second phase exert a great influence on the ferromagnetic transition temperature T-C. The composite system exhibits a percolative behavior in the conductivity, and the metal-insulator transition temperature TM-I decreases with x and is finally suppressed as the MgO content increases up to x=0.3. An enhancement in magnetoresistance (MR) is observed at low temperatures for the composites, and the low-field sensitivity of MR gets enhanced with the increase in MgO content. This work provides a promising method for manipulating the magnetotransport properties of manganites by composites with a proper insulator phase in a 0-3 connectivity fashion. (C) 2009 American Institute of Physics. [doi:10.1063/1.3262624]
资助项目	National Natural Science Foundation of China[50962009] ; Key Project of Chinese Ministry of Education[209130] ; Foundation of Gansu Educational Committee[070313-01][0803-03] ; Doctoral Research Grant of Lanzhou University of Technology[SB 10200701] ; Natural Science Foundation of Gansu Province[2007GS05336]
WOS研究方向	Physics
语种	英语
出版者	AMER INST PHYSICS
WOS记录号	WOS:000272932300124
状态	已发表
内容类型	期刊论文
源URL	[http://119.78.100.223/handle/2XXMBERH/35334]
专题	省部共建有色金属先进加工与再利用国家重点实验室材料科学与工程学院理学院
通讯作者	Yang, H.
作者单位	1.Lanzhou Univ Technol, Sch Sci, Lanzhou 730050, Peoples R China 2.Lanzhou Univ Technol, State Key Lab Gansu Adv Nonferrous Met Mat, Lanzhou 730050, Peoples R China
推荐引用方式 GB/T 7714	Yang, H.,Cao, Z. E.,Shen, X.,et al. Fabrication of 0-3 type manganite/insulator composites and manipulation of their magnetotransport properties[J]. JOURNAL OF APPLIED PHYSICS,2009,106(10).
APA	Yang, H..,Cao, Z. E..,Shen, X..,Xian, T..,Feng, W. J..,...&Dai, J. F..(2009).Fabrication of 0-3 type manganite/insulator composites and manipulation of their magnetotransport properties.JOURNAL OF APPLIED PHYSICS,106(10).
MLA	Yang, H.,et al."Fabrication of 0-3 type manganite/insulator composites and manipulation of their magnetotransport properties".JOURNAL OF APPLIED PHYSICS 106.10(2009).