Magnetic control of ferroelectric interfaces

We report the strong magnetic field dependence of ferroelectric PbZr _0.52Ti_0.48O₃ (PZT) films on half-metallic oxide La_0.67Sr_0.33MnO₃ (LSMO) electrodes. As the field H is increased, the hysteresis loop first broadens (becomes lossy) and then disappears at approximately H = 0.34T and ambient temperatures. The data are compared with the theories of Pir et al (2009 Phys. Rev. B 79 214114), Parish and Littlewood (2008 Phys. Rev. Lett. 101 166602) and Catalan (2006 Appl. Phys. Lett. 88 102902). The results are interpreted as due not to magnetocapacitance but to the sharp negative magnetoresistance in LSMO at low magnetic fields (Hwang et al 1996 Phys. Rev. Lett. 77 2041), which causes a dramatic increase in leakage current through the PZT.