Simple overlap model and crystal field analysis of Cs2ZnCl4:Co2+. Correlation with optical and magnetic properties

The blue allotropic form of Co2+:Na2CoP2O7: optical and magnetic properties, correlation with crystallographic data

“…With this hypothesis, the most likely values are B ¼ 739 cm À1 in agreement with the value 700 cm À1 in a pseudo-tetrahedral site [14] and DqD501 cm À1 : Despite the very bad absorption spectrum, it is possible to deduce a rough energy level scheme: (i) by decomposition of the two broad bands n 2 and n 3 as mentioned above and (ii) from the position of the weak forbidden transitions observed in the 20,000-31,000 cm À1 range.…”

“…The Simple Overlap Model (SOM) developed by Malta [7][8][9], in which part of the chemical bonding is taken into account, has been applied successfully to reproduce the crystal field parameters (cfps) B k q for lanthanides as well as for 3d transition metal elements [ [10][11][12][13][14]. In this model, the cfps are calculated from the atomic positions in the structure.…”

Origin of the Ground Kramers Doublets for Co2+(3d7) Ions with the Effective Spin 3/2 Versus the Fictitious ‘Spin’ ½

“…The highspin (HS) Co 2+ (S = 3/2) cases identified in literature may be categorized into the groups by suitable ranges of |D| values. For the illustrative examples presented in Table 1, we tentatively adopt the ranges (in cm −1 ): small (up to 20) [38][39][40][41][42], moderate (20-50), large (50-100) [43,44], and very large (over 100) [44]; for other references see, also Table 27 and 39 of [37]. Note that the ZFS Hamiltonian in Eqs.…”