Double-barrier magnetic tunnel junctions (DMTJs) with and without an amorphous ferromagnetic material such as CoFe-SiB 10, CoFe 5/CoFeSiB 5, and CoFe 10 (nm) were prepared and compared to investigate the bias voltage dependence of the tunneling magnetoresistance (TMR) ratio. Typical DMTJ structures were Ta 45/Ru 9.5/IrMn 10/CoFe 7/AlO x/free layer 10/AlO x/CoFe 7/IrMn 10/Ru 60 (in nanometers). The interlayer coupling field and the normalized TMR ratios at the applied voltages of+0.4 and -0.4 V of the amorphous CoFeSiB free-layer DMTJ offer lower and higher values than that of the polycrystalline CoFe free-layer DMTJ, respectively. An amorphous ferromagnetic CoFeSiB layer improves the interface roughness of the free layer/tunnel barrier and, as a result, the interlayer coupling field and bias voltage dependence of the TMR ratio are suppressed at a given voltage.
|頁（從 - 到）||1847-1850|
|期刊||Physica Status Solidi (A) Applications and Materials Science|
|出版狀態||Published - 2008 8月|
All Science Journal Classification (ASJC) codes