TMR of double spin-valve type AF/FM/I/FM/I/FM/AF magnetic tunneling junctions

Abstract

An unusually large enhancement of TMR at 77 K was observed in double barrier tunnel junctions (DBTJ). This is explained with extended Julliere's model which yields a twice larger TMR value. When the spin coherence length is much smaller at higher temperature, DBTJ is shown to work as a series of two single barrier tunnel junctions. (C) 2002 Elsevier Science B.V. All rights reserved.