title: Giant room temperature electric-field-assisted magnetoresistance in La0.7Sr0.3MnO3/n-Si nanotip heterojunctions.
abstract: An on-chip approach for fabricating ferromagnetic/semiconductor-nanotip heterojunctions is demonstrated. The high-density array of Si nanotips (SiNTs) is employed as a template for depositing La(0.7)Sr(0.3)MnO(3) (LSMO) rods with a pulsed-laser deposition method. Compared with the planar LSMO/Si thin film, the heterojunction shows a large enhancement of room temperature magnetoresistance (MR) ratio up to 20% under 0.5 T and a bias current of 20 µA. The MR ratio is found to be tunable, which increases with increasing external bias and the aspect ratios of the nanotips. Electric-field-induced metallization, in conjunction with nanotip geometry, is proposed to be the origin for the giant MR ratio.
authors.affiliation: Department of Physics, National Taiwan University, Taipei, Taiwan.
authors.forename: Cheong-Wei
authors.initials: CW
authors.lastname: Chong
authors.forename: Daniel
authors.initials: D
authors.lastname: Hsu
authors.forename: Wei-Chao
authors.initials: WC
authors.lastname: Chen
authors.forename: Chien-Cheng
authors.initials: CC
authors.lastname: Li
authors.forename: Yi-Fan
authors.initials: YF
authors.lastname: Huang
authors.forename: Hsieh-Cheng
authors.initials: HC
authors.lastname: Han
authors.forename: Jauyn Grace
authors.initials: JG
authors.lastname: Lin
authors.forename: Li-Chyong
authors.initials: LC
authors.lastname: Chen
authors.forename: Kuei-Hsien
authors.initials: KH
authors.lastname: Chen
authors.forename: Yang-Fang
authors.initials: YF
authors.lastname: Chen