Synthetic magneetic pinning element having strong antiferromagnetic coupling
OwnerRongfu Xiao, Yimin Guo +1inventors
InventorsRONGFU XIAO, YIMIN GUO, JUN CHEN
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Abstract
The present invention discloses an enhanced synthetic antiferromagnetic (eSAF) element with a very strong RKKY coupling comprising a magnetic pinning layer having a face-center-cubic (fcc) crystalline structure and a magnetic reference layer having a body-center-cubic (bcc) crystalline structure which are antiferromagnetically coupled by a composite non-magnetic spacer (CnmS) containing a bi-layer of (Ru, Rh or Ir)/Cr or tri-layer of (Ru, Rh, or Ir)/(W, Mo, or V)/Cr. With such eSAF, a strong magnetic pinning element is formed which can be used to make various thin STT-MRAM film stacks with good thermal and magnetic stability while maintaining high TMR value.
Claims17
A synthetic magnetic pinning element (MPE) comprising
- a magnetic pinning layer (PL) having a face-center-cubic (fcc) crystalline structure and having an invariable magnetization direction;
- a magnetic reference layer (RL) having a body-center-cubic (bcc) crystalline structure and having an invariable magnetization direction;
- a composite non-magnetic spacer (CnmS) having a bi-layer structure of (Ru, Rh or Ir)/Cr or tri-layer structure of (Ru, Rh, or Ir)/(W, Mo, or V)/Cr, provided between said magnetic pinning layer and said magnetic reference layer;
- said PL/CnmS/RL form strong antiferromagnetic (AF) coupling;
2 The element of claim 1, wherein said AF coupling between said PL and said RL is achieved through interfacial RKKY coupling having at least one of the group Co/CnmS/Fe, Co/CnmS/FeB, FeCo(>50%)/CnmS/Fe(>50%)Co, or Co/CnmS/Fe(>40%)CoB;
- wherein said Co or FeCo(>50%) layer is an interfacial portion of PL contacting with the (Ru, Rh, or Ir) of said CnmS and said Fe, FeB, Fe(>50%)Co or Fe(>40%)CoB layer is an interfacial portion of RL contacting with the Cr of said CnmS.
Dependencies are inferred from the claim text.