The epitaxial growth behavior of thin PbMnTe film on BaF2(1 1 1): Influence of Mn doping density and substrate temperatures.

For high Mn content, MnTe phase segregated from the Pb 1-x Mn x Te phase for the cases of Mn content x is higher than 0.026. These segregated grains aggregated at positions of the threading dislocations, resulting in the formation of pit-like domains on the spiral islands of PbMnTe alloy film. Both the Mn substitutional limitation of Pb in PbTe and the quality of Pb 1−x Mn x Te film can be improved provided that the substrate was kept at high temperature while in deposition. • MnTe phase segregated from the Pb 1−x Mn x Te phase when x value was increased. • The doping criteria of Mn to replace Pb in PbMnTe film was determined. • Suggestions for fabrication of high-quality PbMnTe film was given. PbMnTe film attracted intense scientific attention because of its promising properties such as enhanced magneto-optical effects, huge negative magneto-resistance effect, and Curie-Weiss paramagnetism. The electro-magnetic properties of PbMnTe film were intensively studied in the past decades. In contrast, the fabrication of PbMnTe film was still less investigated and its growth behavior was needed to be better understood. In this work, we study the growth behaviors of Pb 1−x Mn x Te as a function of Mn content (x) and temperatures of BaF 2 (1 1 1) substrate. The structure and growth behavior of Pb 1−x Mn x Te film changed substantially when the Mn content is larger than the criteria of x = 0.026. Mn will replace the position of Pb2+ for cases of x <0.026, leading to the formation of (1 1 1)-orientated NaCl-type Pb 1−x Mn x Te spirals. In contrast, MnTe phase segregated from the Pb 1−x Mn x Te phase and aggregates at positions of the threading dislocations for cases of x >0.026, resulting in the formation of pit-like domains on the spiral islands of PbMnTe alloy film. The pit-like MnTe grains aggregated nearby the threading dislocations due to the existence of the stress field at these defect regions. The criteria of Mn to replace Pb increases when deposited PbMnTe at higher substrate temperature. This indicates that the quality of Pb 1−x Mn x Te film would be improved if the substrate was kept at high temperature while in deposition. [ABSTRACT FROM AUTHOR]