Giant room-temperature magnetoresistance in polycrystalline Zn(0.41)Fe(2.59)O4 with alpha-Fe2O3 grain boundaries

P Chen; D Y Xing; Y W Du; J M Zhu; D Feng

doi:10.1103/PhysRevLett.87.107202

Giant room-temperature magnetoresistance in polycrystalline Zn(0.41)Fe(2.59)O4 with alpha-Fe2O3 grain boundaries

Phys Rev Lett. 2001 Sep 3;87(10):107202. doi: 10.1103/PhysRevLett.87.107202. Epub 2001 Aug 20.

Authors

P Chen¹, D Y Xing, Y W Du, J M Zhu, D Feng

Affiliation

¹ National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China.

PMID: 11531500
DOI: 10.1103/PhysRevLett.87.107202

Abstract

A tunneling-type magnetoresistance (MR) as large as 158% is observed at T = 300 K in a polycrystalline Zn0.41Fe2.59O4 sample, in which the Zn0.41Fe2.59O4 grains are separated by insulating alpha-Fe2O3 boundaries. The huge room-temperature MR is attributed to the high spin polarization of Zn(0.41)Fe(2.59)O4 grains and antiferromagnetic correlations between magnetic domains on both sides of the insulating alpha-Fe2O3 boundary. The MR exhibits strong temperature dependence below 100 K and its magnitude is enhanced to reach 1280% at 4.2 K, which may arise from the Coulomb blockade effect.