EPR of Co²⁺ in KTaO₃

Abstract

Assuming that a , the orbital momentum factor, equals 1.4, the equation yields x = 8 . 5 7 .The tetragonal splitting parameter A is then determined wing c .

Paramagnetic point and pair defects in oxide perovskites

“…Since then, the same kind of transition metal ionoxygen vacancy centre has also been observed for other ions and different valencies : Co2+-Vo has been reported by Hannon in KTa03 [33] and in SrTio3 by Faughnan [34]. The The iron pair-centre, Fe4+ -v Û' isoelectronic to the Mn3+-Vo, with high spin S = 2, was observed shortly after the latter [37].…”

EPR studies of some f n and d n electronic impurities in KTaO3 single crystals

“…Thus, the A ion is dodecahedrally coordinated by oxygens (12 nearestneighbor oxygen ions along the (110) axes) and the B ion is octahedrally coordinated by the oxygens (six nearest-neighbor oxygens along the (100) axes). Considerations of ionic radii indicate that iron-group ions should substitute for the B ion and that rare-earth ions should reside in the A ion sites.…”

Defect properties of cobalt-doped hexagonal barium titanate ceramics

“…The spin-Hamiltonian parameters of Z2 were evaluated by computational analysis of the experimental X-and Q-band spectra (T = 20 K) and are given in table 1. According to the arguments in the previous chapter, we assign the Co centres causing the spectrum Z2 to Co 2+ ions in an axial crystalline field whose crystal field splitting is stronger than the spin-orbit splitting [33,34]. In figure 8, the experimental spectra Z1 and Z2 of an Ar-annealed sample with x = 0.01 are compared with simulated ones using the parameters given in Due to the phase transition at T = 74 K the symmetry of the unit cell is changed to monoclinic and the ( ) ( ) Ti 1 O 2 6 octahedra become weakly distorted [11].…”