Half-metallic magnetic tunnel junction with a superlattice barrier

Peng Tseng^1*, Jing-Ci Su¹, Wen-Jeng Hsueh¹

¹Department of Engineering Science and Ocean Engineering, National Taiwan University, Taipei, Taiwan

* Presenter:Peng Tseng, email:f03525047@ntu.edu.tw

Spin-transfer torque (STT) applications have been a popular candidate in the development of novel memory technologies such as magnetoresistive random access memory (MRAM). However, high switching power is a weakness in typical magnesium oxide (MgO)-based STT-MRAMs. Here, a 10-times switching current in a magnetic tunnel junction (MTJ) is achieved using a superlattice-barrier and half-metallic fixed layer. The half-metallic electrode such as full-Heusler alloys can produce a high-purity spin polarization current to result in strong STT effect. The switching power is less than 10% of that in traditional MgO tunneling barrier MTJs. The proposed MTJ device, called SS-MRAM, has many excellent properties, including enhanced spin-transfer efficiency, reduced writing power, extended durability, and improved writing speed.

Keywords: Spintronics, Half-metallic, Superlattice, Spin-transfer torque, Switching power