Alternative crystal-field parameters for rare-earth ions obtained from various techniques: II. Reanalysis of spectroscopic data for Eu3+ and Er3+ ions in RE2BaXO5 (X=Co, Cu, Ni, Zn) high temperature superconductors and related systems

Comparative analysis of crystal-field parameters for rare-earth ions at monoclinic sites in AB(WO4)2crystals: I. Tm3+in KGd(WO4)2and KLu(WO4)2, and Ho3+and Er3+ions in KGd(WO4)2

“…The intricate low symmetry aspects inherent in the spectroscopic studies [22,23] and the resulting monoclinic CFP sets are reanalyzed in sections 3 and 4, respectively. Our methodology incorporates the following approaches: standardization of CF Hamiltonians [14,16], multiple correlated fitting technique [16] and closeness of CFP sets [15,18,33,34]. Our considerations enable clarification of several doubtful aspects identified in [22,23].…”

“…Closeness of standardized CFP sets is quantitatively assessed using the closeness factors and the norm ratios [15,18,33,34].…”

“…In view of Burdick's et al intensity studies, see, e.g., [46,47], indicating a plethora of multiple local minima that fit the data nearly equally well, it is rather surprising that only single-fitting results were reported in most cases (for references, see, e.g., [15,33,34]). It may be possible that any controversial CFP sets may represent two different closely lying local minima.…”

“…In many instances it happens that the orthorhombic and lower symmetry standardization provides means to reconcile the differences between CFP sets reported by various authors. Thus this procedure helps to solve the controversial claims about the inaccuracy of the data of fellow researchers [15,33,34]. In the case such differences could not be resolved in this way, the reasons for any remaining disparities indicated, e.g.…”