Tunneling magnetoresistance at up to 270 K in La0.8Sr0.2MnO3/SrTiO3/La0.8Sr0.2MnO3 junctions with 1.6-nm-thick barriers

Abstract
Magnetic tunneling junctions are fabricated from epitaxially grown La0.8Sr0.2MnO3/SrTiO3/La0.8Sr0.2MnO3 trilayers. A large tunneling magnetoresistance of 150% is observed for a junction with a thin barrier layer (1.6 nm) under a low switching field (<10 Oe) at 5 K. A small tunneling magnetoresistance is observed even at 270 K, which is close to the ferromagnetic Curie temperature (290 K) of the La0.8Sr0.2MnO3 film. The large magnetoresistance and high operating temperature are attributed to the sufficiently thin and uniform barrier layer of SrTiO3.