Magnetoresistive sensors with hybrid Co/insulator/ZnO:Co junctions

作者：Chen Guang; Song Cheng; Pan Feng

来源：International Journal of Minerals Metallurgy and Materials, 2013, 20(2): 160-165.

DOI：10.1007/s12613-013-0708-5

• magnetoresistance
• sensors
• zinc oxide
• magnesia
• cobalt
• doping
• magnetic semiconductors

Magnetic tunnel junctions (MTJs), as the seminal spintronic devices, are expected for applications in magnetoresistive sensors due to their large magnetoresistance (MR) and high field sensitivity. Two hybrid Co/insulator/ZnO:Co junctions were fabricated with two different barriers to investigate the magneto-transport properties. Experimental results indicate that, both Co/MgO/ZnO:Co and Co/ZnO/ZnO:Co junctions show the positive and nearly linear MR, and their tunnel magnetoresistances (TMR) are 21.8% and 13.6%, respectively, when the current is applied perpendicular to the film plane under the magnetic field of 2 T at 4 K. The nonlinearity of MR is less than 1% within the magnetic field (H) of 1 kOe < H < 12 kOe at low temperature, making them attractive as magnetoresistive sensors. The higher MR of Co/MgO/ZnO:Co junctions is due to the superior spin filtering effect and larger effective barrier height of the MgO barrier. This linear MR characteristic of Co/insulator/ZnO:Co structures shows a promising future on the applications of diluted magnetic semiconductors in magnetoresistive sensors.

• 出版日期2013-2
• 单位清华大学