Electron Paramagnetic Resonance ofFe3+andNi3+

EPR of Co2+ in KTaO3

“…The K1+ site can be ruled out for the Co field is negative at the K1+ site (1) and, therefore, C0? (d7) would % o k like" the d3-configuration.…”

Paramagnetic point and pair defects in oxide perovskites

“…EPR of Mn2+ in CaZro3 [23], BaTi03 and PbTi03 [24] has been assigned to B sites [15], and an axial Mn2+ centre in SrTi03 [25] to A sites [15,26] [7,30], and in BaTi03 [31]. The Fe3+-Vo centre was important for the analysis of critical phenomena in the structural phase transition of SrTio3.…”

“…Early examples of such EPR studies are Fe3 + on the B site and Gd3 + on the A site in SrT'03 [1,6] and BaTi03 [4,6]. However [7] apart from normal Ta site occupation. Gd3 + on Ti sites has been reported for ceramic BaT'03 synthetized with enriched Ba versus Ti ratios as well as for reduced and quenched BaTi03 single crystals [8].…”

Theoretical Studies on the Gyromagnetic Factors and the Hyperfine Structure Constants for the Tetragonal Copper Center in KTaO3

“…Cu 2+ may substitute the host octahedral Ta 5+ site in KTaO 3 due to its similar ionic radius, despite of its sig-0932-0784 / 05 / 0800-0615 $ 06.00 c 2005 Verlag der Zeitschrift für Naturforschung, Tübingen · http://znaturforsch.com nificant charge mismatch (note: some transition-metal ions such as Fe 3+ and Ni 3+ can also occupy the dodecahedral K + site [5]). Since the impurity Cu 2+ has less charge than the host Ta 5+ , one nearest-neighbouring oxygen vacancy (V O ) can occur along one of the [100] directions as charge compensation.…”