Nano PTFE Polymer Films as Organic Insulating Barrier for Tunneling Magneto-Resistive Fe/PTFE/Fe Devices

Nano films of polytetrafluoroethylene (PTFE; commercially coded as Teflon) shows advantage over inorganic spacer materials like Al2O3 and MgO in fabricating tunneling magneto resistive devices due to its relative dielectric constant and chemical inertness to provide a homogenous metal-organic interface. Pulsed electron deposition proves useful in fabricating such thin PTFE films (3-6 nm) for trilayer device such as Fe (100 nm)/ PTFE (3-6 nm) /Fe (100 nm) on Si (100). Characteristic magnetic hysteresis loops demonstrating the magnetic tunnel junctions were realized for a PTFE organic layer thickness >3 nm. The tunneling magnetoresistance measurement at room temperature shows a typical magneto resistive feature, increasing with increasing PTFE thickness.