Molecular beam epitaxy of strained PbTe/EuTe superlattices

Using reflection high energy electron diffraction (RHEED), the phase diagram of strained layer heteroepitaxy of EuTe by molecular beam epitaxy on PbTe(111) surfaces was determined. The EuTe(111) surface exhibits different surface reconstructions corresponding to a Te-stabilized or an Eu-stabilized surface state. For perfect two-dimensional layer-by-layer heteroepitaxial growth, only a narrow process window exists which can be determined by RHEED. Using such established growth conditions, we have fabricated strained PbTe/EuTe superlattices with superior structural perfection as shown by high resolution x-ray diffraction.