Magnetic anisotropic behavior in epitaxial La2/3Ca1/3MnO3/YBa2Cu3O7-δ/ La2/3Ca1/3MnO3 and La2/3Ca1/3MnO3/La1/3Ca2/3MnO3/YBa2Cu3O7-δ trilayered structures

The temperature dependence of the magnetization along with magnetization hysteresis loops were measured on dc sputtered La2∕3Ca1∕3MnO3[ferromagnetic(F)]∕YBa2Cu3O7−δ[superconductor(S)]∕La2∕3Ca1∕3MnO3(F) and La2∕3Ca1∕3MnO3(F)∕La1∕3Ca2∕3MnO3[antiferromagnetic(AF)]∕YBa2Cu3O7δ(S) trilayered structures. The magnetic fields were applied both parallel (in-plane) and perpendicular (out-of-plane) to the film plane. Magnetization hysteresis loops, recorded at 5K, shown a clear central peak around zero field when the magnetic field was applied perpendicular to the film plane and a typical ferromagnetic behavior when applied parallel. Additionally, the dependence of the magnetization on the temperature, performed under the zero-field-cooling (ZFC) and field-cooling (FC) regimens, evidenced the active presence of the diamagnetic and ferromagnetic phases both in the F∕S∕F and F∕AF∕S trilayers. Thus, the diamagnetic phase was clearly observed under the ZFC regimen, whereas a possible paramagnetic Meissner effect was obse...