Positive magnetoresistance in Co40Fe40B20/SiO2/Si heterostructure
1 Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparation Technology, Faculty of Science, Tianjin University - Tianjin 300072, China
2 PSE Division, KAUST - Thuwal 23955-6900, Kingdom of Saudi Arabia
Received: 1 May 2016
Accepted: 27 June 2016
Current-perpendicular-to-plane electronic transport properties and magnetoresistance of amorphous Co40Fe40B20/SiO2/Si heterostructures are investigated systematically. A backward diode-like rectifying behavior was observed due to the formation of a Schottky barrier between Co40Fe40B20 and Si. The junction resistance shows a metal-insulator transition with decreasing temperature in both the forward and reverse ranges. A large positive magnetoresistance (MR) of ∼2300% appears at 200 K. The positive MR can be attributed to the magnetic-field–controlled impact ionization process of carriers. MR shows a temperature-peak–type character under a constant bias current, which is related to the spin-dependent barrier in the Si near the interface.
PACS: 73.40.Qv – Metal-insulator-semiconductor structures (including semiconductor-to-insulator) / 71.30.+h – Metal-insulator transitions and other electronic transitions / 72.15.Gd – Galvanomagnetic and other magnetotransport effects
© EPLA, 2016