Determination of spin-dependent Seebeck coefficients of CoFeB/MgO/CoFeB magnetic tunnel junction nanopillars

作者：Liebing N; Serrano Guisan S^*; Rott K; Reiss G; Langer J; Ocker B; Schumacher H W

来源：Journal of Applied Physics, 2012, 111(7): 07C520.

DOI：10.1063/1.3679769

We investigate the spin-dependent Seebeck coefficient and the tunneling magneto thermopower (TMTP) of CoFeB/MgO/CoFeB magnetic tunnel junctions (MTJ) in the presence of thermal gradients across the MTJ. The thermo power voltage V-TP across the MTJ is found to scale linearly with the heating power and reveals similar field dependence as the tunnel magnetoresistance (TMR). Based on calibration measurements and finite element simulations of the heat flux, the thermal gradient and large spin-dependent Seebeck coefficients of the order of (240 +/- 110) mu V/K are derived. From additional measurements on MTJs after dielectric breakdown, a TMR up to 90% and Seebeck coefficients up to 650 mu V/K can be derived.

• 出版日期2012-4-1