title: Enhancement of Low-field Magnetoresistance in Self-Assembled Epitaxial La0.67Ca0.33MnO3:NiO and La0.67Ca0.33MnO3:Co3O4 Composite Films via Polymer-Assisted Deposition.
abstract: Polymer-assisted deposition method has been used to fabricate self-assembled epitaxial La0.67Ca0.33MnO3:NiO and La0.67Ca0.33MnO3:Co3O4 films on LaAlO3 substrates. Compared to pulsed-laser deposition method, polymer-assisted deposition provides a simpler and lower-cost approach to self-assembled composite films with enhanced low-field magnetoresistance effect. After the addition of NiO or Co3O4, triangular NiO and tetrahedral Co3O4 nanoparticles remain on the surface of La0.67Ca0.33MnO3 films. This results in a dramatic increase in resistivity of the films from 0.0061 Ω•cm to 0.59 Ω•cm and 1.07 Ω•cm, and a decrease in metal-insulator transition temperature from 270 K to 180 K and 172 K by the addition of 10%-NiO and 10%-Co3O4, respectively. Accordingly, the maximum absolute magnetoresistance value is improved from -44.6% to -59.1% and -52.7% by the addition of 10%-NiO and 10%-Co3O4, respectively. The enhanced low-field magnetoresistance property is ascribed to the introduced insulating phase at the grain boundaries. The magnetism is found to be more suppressed for the La0.67Ca0.33MnO3:Co3O4 composite films than the La0.67Ca0.33MnO3:NiO films, which can be attributed to the antiferromagnetic properties of the Co3O4 phase. The solution-processed composite films show enhanced low-field magnetoresistance effect which are crucial in practical applications. We expect our polymer-assisted deposited films paving the pathway in the field of hole-doped perovskites with their intrinsic colossal magnetoresistance.
authors.affiliation: College of Physics, Optoelectronics and Energy &Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Zhou
authors.affiliation: Department of Chemical and Materials Engineering, New Mexico State University, New Mexico 88003, USA.
authors.forename: Yuling
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Il
authors.initials: I
authors.lastname: Jeon
authors.affiliation: College of Physics, Optoelectronics and Energy &Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China.
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Yi
authors.affiliation: Key Laboratory of Materials Physics, Institute of Solid State Physics; High Magnetic Field Laboratory, Chinese Academy of Science, Hefei 230031, China.
authors.forename: Xuebin
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Materials Physics, Institute of Solid State Physics; High Magnetic Field Laboratory, Chinese Academy of Science, Hefei 230031, China.
authors.forename: Xianwu
authors.initials: X
authors.lastname: Tang
authors.affiliation: Department of Electrical and Computer Engineering, Texas A&M University, Texas 77843, USA.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Chemical and Materials Engineering, New Mexico State University, New Mexico 88003, USA.
authors.forename: Ling
authors.initials: L
authors.lastname: Fei
authors.affiliation: Key Laboratory of Materials Physics, Institute of Solid State Physics; High Magnetic Field Laboratory, Chinese Academy of Science, Hefei 230031, China.
authors.forename: Yuping
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Department of Chemical and Materials Engineering, New Mexico State University, New Mexico 88003, USA.
authors.forename: Shuguang
authors.initials: S
authors.lastname: Deng
authors.affiliation: Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Matsuo
authors.affiliation: Department of Chemical and Materials Engineering, New Mexico State University, New Mexico 88003, USA.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Luo
authors.affiliation: College of Physics, Optoelectronics and Energy &Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China.
authors.forename: Guifu
authors.initials: G
authors.lastname: Zou