Possible proximity effect on the [LSMO(10 or 5nm)/YBCO(10nm0)]4 supper lattice films on STO (001) substrate
Hsiung Chou1*, G. D. Gwivedi1, C.-H. Chen2, S.-L Tseng3, J. G. Lin3
1Physics, National Sun -sen Yan University, Kaohsiung City, Taiwan
2General Study, Wenzao Ursuline University of Languages, Kaohsiung City, Taiwan
3Center for Condensed Matter Sciences, Taiwan Univeristy, Taipei, Taiwan
* presenting author:周雄, email:hchou@mail.nsysu.edu.tw
The strong coupling between the magnetic, orbital and lattice are likely responsible for the rich phenomena in oxide SC/FM superlattice films, such as a magnetic proximity effect, a giant magnetoresistance and a SC induced magnetic depletion in the FM layers.[1,2] In this study, two set of supperlattice of [LSMO(10 or 5nm)/YBCO(10nm)]4 film were grown on SrTiO3 (001) substrates by a UHV pulse laser deposition technique. To reveal the magnetic structure fluctuation at SC/FM interfaces, a polarized neutron reflectometry (PNR) measurements were carried out at 1.4mT and 1T applied magnetic field at 300K, and at 1.4mT with zero field cooled and 1T field cooled in the Platypus beam line of ANSTO. The reflectivity intensities of each curve span over 5 orders of magnitude indicating good interfaces with very low roughness. The major superlattice peaks are apparently and have prominent differences between different polarizations to the external magnetic field. The [LSMO(5nm)/YBCO(10nm)]4 film, PNP measurements at 8K by field cooled at 1T or zero filed cooled processing and are measured at 1.4mT,the superlattice peaks show obvious different results between ++ and -- measurements. Interestingly, the +- measurement shows a strong spin flip superlattice peak which may be due to the Meisnor effect of YBCO film or proximity effect on LSMO layer. More details' report will be presented in the meeting.
[1] C. Bernhard et al. Phys. Rev. B 87, 115105 (2013)
[2] C. Bernhard et al. Phys. Rev. Lett. 108, 197201 (2012)
[3] C. Bernhard et al. Nat. Mat. 8, 315 (2009)

Keywords: superconductor, ferromagentism, superlattice film, neutron diffraction, polarized neutron reflectivity