Alternative crystal-field parameters for rare-earth ions obtained from various techniques: III. Low symmetry aspects inherent in monoclinic parameters obtained by Mössbauer spectroscopy for Tm3+ ions in Tm2BaXO5 (XÂ =Â Co, Cu, Ni)

This is third paper in a series devoted to reanalysis of the non-standard and standard crystal-field (CF) parameter (CFP) sets obtained from various experimental techniques for trivalent rare-earth (RE) ions in high temperature superconductors (HTSC) and related systems. Unlike the previous two papers, which dealt with orthorhombic CFPs, in this paper the monoclinic CFPs for Tm3+ ions in Tm2BaXO5 (X = Co, Cu, Ni) obtained in Mössbauer spectroscopy studies are reanalyzed. Additional aspects arising from lowering of the site symmetry from orthorhombic to monoclinic are considered. Using the package CST for each original experimentally determined CFP set, five additional alternative CFP sets are determined. These results provide deeper meaning to the fitted CFP sets and may be helpful in future spectroscopic studies of Tm2BaXO5 and related systems.