Anisotropic magnetoresistance in La0.67Ca0.33MnO3/YBa2Cu4O8/La0.67Ca0.33MnO3 trilayer films

The magnetic anisotropy of La0.67Ca0.33MnO3/YBa2Cu4O8/La0.67Ca0.33MnO3 (LCMO/YBCO/LCMO) sandwiches on (001) SrTiO3 have been investigated. Single layer LCMO and sandwiches show in-plane anisotropy. Thick spacer layer can decouple the adjacent LCMO layers and weaken the easy-plane anisotropy. Magnetoresistance (MR) and magnetization strongly depends on the magnetic field direction. A nearly sinusoidal dependence on the angle between the applied magnetic field and the transport current or film plane is observed. A positive MR is present with lower fields applied not only in-plane but also out-of-plane in sandwich films.