We demonstrate magnetization switching in out-of-plane magnetized TaCoFeBMgO nanowires by current pulse injection along the nanowires, both with and without a constant and uniform magnetic field collinear to the current direction. We deduce that an e
ffective torque arising from spin-orbit effects in the multilayer drives the switching mechanism. While the generation of a component of the magnetization along the current direction is crucial for the switching to occur, we observe that even without a longitudinal field thermally generated magnetization fluctuations can lead to switching. Analysis using a generalized Neel-Brown model enables key parameters of the thermally induced spin-orbit torques switching process to be estimated, such as the attempt frequency and the effective energy barrier.
