Electron paramagnetic resonance and relaxation study of copper (II) and silver (II) in CsCdF3 single crystals

Abstract

Copper and silver, respectively, were introduced into single crystals of CsCdF3. Our detailed electron paramagnetic resonance (EPR) study showed that both elements enter the Cd lattice site—copper as Cu2+, silver as Ag+, which then was converted into Ag2+ by x raying the corresponding samples. Cu2+ and Ag2+ were shown to present in their ground state a pseudostatic Jahn–Teller effect. Motional effects were observed in the respective EPR spectra and studied in some detail for Cu2+ as they are seen over a wide temperature range. Predictions of a stochastic Kubo model [J. Phys. Soc. Jpn. 9, 935 (1954)] were compared with the temperature dependent linewidths of the motionally averaged EPR spectrum. A power law (Tn with n≂1.9) was determined for the temperature dependence of the reorientation frequency between 30 and 90 K.

Anomalous superhyperfine tensor observed in BaFCl doped with the5d1ionLa2+: Role ofGarcı́a-Lastra1, Bill2, Barriuso3 et al. 2007Phys. Rev. BSelf Cite

“…As it is usually obtained for d 9 impurities in D 4h or C 4v symmetry 13,17,19 with an unpaired electron in the x 2 − y 2 orbital the three components of the diagonalized shf tensor are found to be all positive. The calculated values at the obtained equilibrium geometry are T x Ј x Ј = 46.7ϫ 10 −4 cm −1 , T y Ј y Ј =47ϫ 10 −4 cm −1 , and T z Ј z Ј = 53.4ϫ 10 −4 cm −1 and thus not far from the absolute value of such quantities measured experimentally ͑Table I͒.…”

“…2 and the measured values of ͉T z Ј z Ј ͉, ͉T x Ј x Ј ͉, and ͉T y Ј y Ј ͉ are displayed in Table I. As is usually observed for d 9 impurities in D 4h or C 4v symmetry 13,17,19 the values of ͉T x Ј x Ј ͉ and ͉T y Ј y Ј ͉ are mutually very close despite the shf tensor is orthorhombic, according to the local symmetry around a ligand ion. Let us now call for simplicity T ʈ = T z Ј z Ј and T Ќ = ͑T x Ј x Ј + T y Ј y Ј ͒ / 2.…”

“…This situation is, however, far from what is observed for the shf tensor of d 9 impurities in elongated octahedral and C 4v symmetries with halides as ligands, where the unpaired electron is also lying in an ϳx 2 − y 2 orbital. [19][20][21][22] In these cases ͑as well as for divalent s 1 impurities in O h symmetry 23 ͒ the shf tensor is found to exhibit a clear anisotropic character. Representative values of T ʈ and T Ќ for this kind of systems are collected in Table II.…”

A Genuine Jahn–Teller System with Compressed Geometry and Quantum Effects Originating from Zero‐Point Motion

“…T t , [21,[53][54][55][56][57][58] the g factor, g av ,o fw hichi sg iven by [Eq. T t , [21,[53][54][55][56][57][58] the g factor, g av ,o fw hichi sg iven by [Eq.…”

High-pressure structural study of fluoro-perovskiteCsCdF3up to 60 GPa: A combined experimental and theoretical study

“…The application of CsCdF 3 in the field of luminesence 7,8,9 has motivated several experimental and theoretical investigations of defect structures involving 3d transition metal ions. 10,11,12,13,14,15,16,17,18 . Elastic properties, including thermal expansion and acoustical measurements of higher order elastic constants, have been reported 19,20,21,22 .…”