Tunneling magnetoresistive (TMR) device and tunneling magnetoresistive read head

The invention dsicloses a tunneling magnetoresistive (TMR) device and a tunneling magnetoresistive read head. According to the invention, a tunneling magnetoresistance (TMR) or magnetic tunnel junction MTJ device comprises a thin MgO tunneling barrier layer and a free ferromagnetic multilayer which includes a CoFeB first ferromagnetic layer, a face centered cubic (fcc) NiFe compensation layer with negative magnetostriction, and a body centered cubic (bcc) NiFe insertion layer between the CoFeB layer and the fcc NiFe compensation layer. An optional ferromagnetic nanolayer (e.g CoFe) may be located between the MgO barrier layer and the CoFeB layer. An optional amorphous separation layer may be located between the CoFeB layer and the bcc NiFe insertion layer. The bcc NiFe insertion layer (including amorphous separation layer) prevents the fcc NiFe compensation layer from adversely affecting the crystalline formation of the MgO and CoFeB layers during annealing. The bcc NiFe insertion layer also increases the TMR