CoFe/Ni multilayer film with perpendicular anisotropy for microwave assisted magnetic recording

A spin transfer oscillator (STO) structure in a spintronic device, comprising:

• (a) a composite seed layer comprising at least a lower Ta layer formed on a substrate and a metal (M1) layer having a fcc(111) or hcp(001) crystal structure contacting the lower Ta layer;
• (b) a field generation layer (FGL) that has an (A1/A2)Y/FeCo alloy configuration where A1 is one of Co, CoFe, or CoFeR wherein R is one of Ru, Rh, Pd, Ti, Zr, Hf, Ni, Cr, Mg, Mn, or Cu, and A2 is one of Ni, NiCo, and NiFe, and Y is a number of laminations, the (A1/A2)Y laminate has perpendicular magnetic anisotropy (PMA) and contacts a top surface of the composite seed layer and is one of (Co/NiFe)Y, (Co/NiCo)Y, (CoFe/NiFe)Y, (CoFe/NiCo)Y, (CoFeR/Ni)Y, (CoFeR/NiFe)Y, or (CoFeR/NiCo)Y where R is one of Ru, Rh, Pd, Ti, Zr, Hf, Ni, Cr, Mg, Mn, or Cu, and the FeCo alloy includes one or more of Al, Ge, Si, Ga, C, Se, and Sn and contacts a bottom surface of a non-magnetic spacer;
• (c) the non-magnetic spacer;
• (d) a laminated spin injection layer (SIL) with high perpendicular magnetic anisotropy (PMA) and with a (A1/A2)X/FeCo configuration contacting a top surface of the non-magnetic spacer wherein X is in a range from 5 to 50, and a thickness (t2) of each A2 magnetic layer is greater than a thickness (t1) of each A1 magnetic layer;
• and
• (e) a capping layer contacting the FeCo layer of the SIL.