We report the temperature dependences of tunneling magnetoresistance ratio, coercivity, thermal stability, and switching current distribution of magnetic tunnel junctions (MTJs) in the temperature range 25-80°C, the most probable working environment for spin-transfer torque random access memory (STT-RAM). Two distinct temperature dependence of the switching current density are apparent due to two switching mechanisms: a switching current density decrease with increasing temperature in the long-pulse (>1 μs) regime, a result of thermally activated switching, but no decrease in the short-pulse (< 10 ns) regime, as a result of precessional switching. In the temperature range studied, the switching current density variation is less sensitive to environmental temperature than it is to switching time. Thus, switching time is the more important factor to consider in STT-RAM design.
Bibliographical noteFunding Information:
This work was supported in part by the Defense Advanced Research Projects Academy Spin Torque Transfer-Random Access Memory Program under Grant HR0011-09-C-0114 and the National Science Foundation Materials Research Science and Engineering Center Program, University of Minnesota, under Grant DMR-0819885. The work of H. Zhao and J.-P. Wang was supported by an Intel University Research Grant.
- Spin electronics
- magnetic tunnel junction (MTJ)
- spin-transfer torque random access memory (STT-RAM)
- spin-transfer torque switching