Anomalous voltage dependence of tunnel magnetoresistance in (Zn, Co)O-based junction with double barrier

作者：Song C; Yang Y C; Li X W; Liu X J; Zeng F; Pan F^*

来源：Applied Physics Letters, 2007, 91(17): 172109.

DOI：10.1063/1.2802044

Voltage dependent tunnel magnetoresistance (TMR) has been studied in fully epitaxial (Zn, Co)O/ZnO/(Zn, Co)O/ZnO/(Zn, Co)O magnetic tunnel junctions (MTJs) with double barrier. The MTJs show extremely small voltage dependence with " half voltage" over 4 V above 6 K. At 5 K, the TMR as a function of voltage is found to be constant up to 2 V, and then decreases. " TMR transition" occurs when temperature decreases to 3 - 4 K, and subsequently, the TMR abnormally increases with voltage at 2 K. The anomalous voltage dependent TMR is discussed in terms of the large energy separation between the Fermi level and the mobility edge.

• 出版日期2007-10-22
• 单位清华大学