Structural and Magnetic Characteristics of Dy/Yb Superlattices

Dy/Yb superlattices with atomicscale periodicity were fabricated by the molecular beam epitaxy method. Reflection high-energy electron diffraction (RHEED) and X-ray diffraction analyses revealed that the fcc Yb layers grew epitaxially on a cleaved NaCl substrate, while Dy layers were found to have the hep structure with a [102] and/or [110] orientation. Thermal hysteresis resulting from different cooling conditions was observed in Dy/Yb superlattices. The magnetic spins of zero-field-cooled superlattices reoriented from the magnetic-frozen states to ferromagnetic states when heated from 4.2K to a specified temperature and then cooled back to 4.2K under a magnetic field.