Fluorescence EXAFS study on local structures around Mn atoms in MnF2–CaF2 superlattices and double hetero-structures on Si(111)

Local structures around Mn atoms in MnF2–CaF2 superlattices and double heterostructures (DHSs) grown by molecular beam epitaxy (MBE) were investigated by fluorescence extended X-ray absorption fine structure (EXAFS) measurement. The EXAFS analysis revealed that in thin MnF2 layers (≤3 ML) fluorite structure that does not exist at normal conditions prevailed over the rutile structure, and the content ratio of the fluorite MnF2 strongly depended on the thickness of the MnF2 layer. Therefore, the thin MnF2 layers grew in fluorite structure on CaF2 and changed to the rutile structure with the increase of the MnF2 layer thickness.