Annealing effect on laser pulse-induced THz wave emission in Ta/CoFeB/MgO films

作者：Sasaki Y^*; Suzuki K Z; Mizukami S

来源：Applied Physics Letters, 2017, 111(10): 102401.

DOI：10.1063/1.5001696

Laser-induced terahertz (THz) emission in Ta/CoFeB/MgO films with various thicknesses of CoFeB and for various annealing temperatures was studied. The THz emission intensity exhibited its maximum value for a CoFeB layer thickness of approximately 1.0 nm, and this maximum value was enhanced by 1.5 times by annealing at 300 degrees C. A correlation was found in the annealing dependence between saturation magnetization, conductivity, and THz emission intensity. The origin of the enhancement of THz emission intensity due to annealing was discussed in terms of the increase in the mean free path of majority spin hot electrons in the CoFeB layer with crystallization due to the annealing. Published by AIP Publishing.

• 出版日期2017-9-4