Near room-temperature magnetoresistance effect in double perovskite La_2NiMnO_6

摘要

Near room-temperature magnetoresistance (MR) effect in ferromagnetic semiconductor La_2NiMnO_6 has been reported. The magnetic field dependent MR curve exhibits two distinct regions: the low-field MR which shows a rapid increase in an applied field within 200 Oe and the high-field MR which shows a relatively slow increase with the field increasing (more than 200 Oe). Based on the analyses of magnetic and electronic properties, we suggest that the low-field MR comes from the increased electron tunneling probability accompanied by the alignment of ferromagnetic domains under external field and the high-field MR is due to the suppression of scattering from the spin defects arising from the Ni/Mn antisite disorders.