Magnetic memory devices including magnetic layers separated by tunnel barriers

Abstract

A magnetic memory device may include a first vertical magnetic layer, a non-magnetic layer on the first vertical magnetic layer, and a first junction magnetic layer on the non-magnetic layer, with the non-magnetic layer being between the first vertical magnetic layer and the first junction magnetic layer. A tunnel barrier may be on the first junction magnetic layer, with the first junction magnetic layer being between the non-magnetic layer and the tunnel barrier. A second junction magnetic layer may be on the tunnel barrier with the tunnel barrier being between the first and second junction magnetic layers, and a second vertical magnetic layer may be on the second junction magnetic layer with the second junction magnetic layer being between the tunnel barrier and the second vertical magnetic layer.

What is claimed is: 
     
         1 . A magnetic memory device comprising:
 a free magnetic layer comprising iron (Fe);   a tunnel barrier on the free magnetic layer; and   a reference magnetic layer comprising iron (Fe) on the tunnel barrier wherein the tunnel barrier is between the free magnetic layer and the reference magnetic layer, and wherein a concentration of iron in the free magnetic layer is greater than a concentration of iron in the reference magnetic layer.   
     
     
         2 . The magnetic memory device of  claim 1  wherein the free magnetic layer and/or the reference magnetic layer comprises at least one selected from cobalt (Co) and/or nickel (Ni). 
     
     
         3 . The magnetic memory device of  claim 1  wherein the free magnetic layer and/or the reference magnetic layer comprises a non-magnetic element. 
     
     
         4 . The magnetic memory device of  claim 1  wherein each of the free magnetic layer and the reference magnetic layer has a magnetization direction that is perpendicular with respect to a plane of the tunnel barrier. 
     
     
         5 . The magnetic memory device of  claim 1  wherein each of the free magnetic layer and the reference magnetic layer has a magnetization direction that is parallel with respect to a plane of the tunnel barrier. 
     
     
         6 . The magnetic memory device of  claim 1  further comprising:
 a substrate; 
 an electrode on the substrate; 
 a vertical free magnetic layer on the electrode, wherein the electrode is between the substrate and the vertical free magnetic layer; and 
 an exchange-coupling control layer on the vertical free magnetic layer, wherein the vertical free magnetic layer is between the electrode and the exchange-coupling layer, wherein the free magnetic layer comprises a junction free magnetic layer on the exchange-coupling control layer, and wherein the exchange-coupling control layer is between the vertical free magnetic layer and the junction free magnetic layer.