Magnetoresistive effect element and magnetic memory

Abstract

A magnetoresistive effect element including a substrate; a pinned layer above the substrate; a free layer between the substrate and the pinned layer; a non-magnetic layer between the free layer and the pinned layer; a first layer provided on an opposite side of a side of the non-magnetic layer of the free layer, the first layer being between the substrate and the free layer, the first layer being in direct contact with the free layer, the first layer being non-magnetic and the first layer including a MgFeO layer, the MgFeO layer being an amorphous layer and being in direct contact with the free layer; and a second layer between the first layer and the substrate, the second layer being in contact with the substrate.

What is claimed is: 
     
         1 . A magnetoresistive effect element comprising:
 a substrate;   a pinned layer above the substrate;   a free layer between the substrate and the pinned layer;   a non-magnetic layer between the free layer and the pinned layer;   a first layer provided on an opposite side of a side of the non-magnetic layer of the free layer, the first layer between the substrate and the free layer, the first layer being in direct contact with the free layer, the first layer being non-magnetic and the first layer including a MgFeO layer, the MgFeO layer being an amorphous layer and being in direct contact with the free layer; and   a second layer between the first layer and the substrate, the second layer in contact with the substrate.   
     
     
         2 . The element according to  claim 1 , wherein the first layer is a layer including a plurality of crystal grains of 5 nm or less and the first layer is a (001)-oriented layer. 
     
     
         3 . The element according to  claim 1 , wherein the free layer is a layer having at least two elements selected from a group including iron, cobalt, and boron. 
     
     
         4 . The element according to  claim 1 , wherein the free and pinned layers have perpendicular magnetic anisotropy. 
     
     
         5 . The element according to  claim 1 , wherein the MgFeO layer includes at least one element selected from the group consisting of niobium, hafnium, tantalum, ruthenium, and tungsten. 
     
     
         6 . A magnetoresistive effect element comprising:
 a substrate;   a pinned layer above the substrate;   a free layer between the substrate and the pinned layer;   a non-magnetic layer between the free layer and the pinned layer;   a first layer provided on an opposite side of a side of the non-magnetic layer of the free layer, the first layer between the substrate and the free layer, the first layer being in direct contact with the free layer, the first layer being non-magnetic and the first layer including a MgFeO layer, the MgFeO layer being a fine crystal layer and being in direct contact with the free layer; and   a second layer between the first layer and the substrate, the second layer in contact with the substrate.   
     
     
         7 . The element according to  claim 6 , wherein the MgFeO layer is formed of a plurality of crystal grains of 5 nm or less and the MgFeO layer is a (001)-oriented layer. 
     
     
         8 . The element according to  claim 6 , wherein the free layer is a layer having at least two elements selected from a group including iron, cobalt, and boron. 
     
     
         9 . The element according to  claim 6 , wherein the free and pinned layers have perpendicular magnetic anisotropy. 
     
     
         10 . The element according to  claim 6 , wherein the MgFeO layer includes at least one element selected from the group consisting of niobium, hafnium, tantalum, ruthenium, and tungsten.