A method of forming a spin torque oscillator device, comprising: (a) forming a first metal oxide layer on a substrate that includes the steps of: forming a first metal layer on the substrate and oxidizing an upper portion thereof with a first passive oxidation having a maximum oxygen pressure of about 10 -5 torr; and forming one or more metal oxide layers on the oxidized upper portion of the first metal layer, wherein one of the one or more metal oxide layers contacts a top surface of the oxidized upper portion; (b) forming a spin polarization layer on a top surface of the first metal oxide layer; (c) forming a non-magnetic layer on the SP layer; (d) forming an oscillation layer on the non-magnetic layer; and (e) forming a second metal oxide layer on the OL with a process comprising: forming a second metal layer on the OL and oxidizing an upper portion thereof with a second passive oxidation process having a maximum oxygen pressure of 10 -5 torr; and forming one or more metal oxide layers on the oxidized upper portion of the second metal layer characterized in that at least one of the one or more metal oxide layers in the first metal oxide layer is formed by direct deposition of a metal oxide layer or by depositing a metal layer and then performing a natural oxidation with a pressure that is at least 10 -3 torr. (a) forming a first metal oxide layer on a substrate that includes the steps of: forming a first metal layer on the substrate and oxidizing an upper portion thereof with a first passive oxidation having a maximum oxygen pressure of about 10 -5 torr; and forming one or more metal oxide layers on the oxidized upper portion of the first metal layer, wherein one of the one or more metal oxide layers contacts a top surface of the oxidized upper portion; forming a first metal layer on the substrate and oxidizing an upper portion thereof with a first passive oxidation having a maximum oxygen pressure of about 10 -5 torr; and forming one or more metal oxide layers on the oxidized upper portion of the first metal layer, wherein one of the one or more metal oxide layers contacts a top surface of the oxidized upper portion; (b) forming a spin polarization layer on a top surface of the first metal oxide layer; (c) forming a non-magnetic layer on the SP layer; (d) forming an oscillation layer on the non-magnetic layer; and (e) forming a second metal oxide layer on the OL with a process comprising: forming a second metal layer on the OL and oxidizing an upper portion thereof with a second passive oxidation process having a maximum oxygen pressure of 10 -5 torr; and forming one or more metal oxide layers on the oxidized upper portion of the second metal layer characterized in that at least one of the one or more metal oxide layers in the first metal oxide layer is formed by direct deposition of a metal oxide layer or by depositing a metal layer and then performing a natural oxidation with a pressure that is at least 10 -3 torr. forming a second metal layer on the OL and oxidizing an upper portion thereof with a second passive oxidation process having a maximum oxygen pressure of 10 -5 torr; and forming one or more metal oxide layers on the oxidized upper portion of the second metal layer