Electronic structure of the copper(II) ion doped in cubic KZnF3

Abstract

Articles you may be interested inCopper doping of small gold cluster cations: Influence on geometric and electronic structure J. Chem. Phys. 135, 224305 (2011); 10.1063/1.3664307 Comment on "Molecular structure and dynamics of off-center Cu 2 + ions and strongly coupled Cu 2 + -Cu 2 + pairs in Ba F 2 crystals: Electron paramagnetic resonance and electron spin relaxation studies" [J.The absorption and magnetic circular dichroism spectra of 1 %-3% copper(II) doped into the cubic perovskite host KZnF3 are measured over the temperature range 1.8-300 K. Sharp magnetic dipole allowed transitions 2Eg(rs)--+2T2gCr7.rS) are observed together with accompanying vibrational fine structure. The spectra are interpreted on the basis of a tetragonally elongated Cu~ground state geometry which arises from strong lahn-Teller coupling. This results in a statistical distribution of three equivalent elongations which can undergo reorientation on the electron paramagnetic resonance time scale. The lahn-Teller coupling within the 2T 2g multiplet is partially quenched by spin-orbit coupling and the lowest Kramers doublet r7 has an octahedral geometry, while the higher lying r s state has a small tetragonal distortion. This system presents an excellent opportunity to study the spectroscopy of the copper(II) ion in a cubic environment.

The highly resolved electronic spectrum of the square planar CuCl42− ion

“…The predicted and observed sign of the MCD is negative for a magnetic dipole allowed transition. 29 This is in agreement with the negative sign of the MCD observed in this work for the electronic origin of same transition in CuCl 4 2− . Fig.…”

Changing the Usual Interpretation of the Structure and Ground State of Cu2+-Layered Perovskites

“…A nearly identical pattern is encountered for other members of the (CnH2n+1NH3)2CuCl4 family (Table 2) 18,19 . This situation is thus seemingly similar to that found for Cu 2+ -doped cubic lattices, like KZnF3 [20][21][22][23] or NaCl [25][26][27] , where the ligand octahedron is elongated and the local symmetry tetragonal as a result of a static Jahn-Teller effect (JTE) 28,29 . For this simple reason, it has systematically been accepted [9][10][11][12][13][14][15][16]30,31 that the JTE is behind the local distortion around the metal cation in RCuCl4 compounds.…”

Compounds Containing Tetragonal Cu2+ Complexes: Is the dx2–y2–d3z2–r2 Gap a Direct Reflection of the Distortion?

“…18,19 In the same vein, while the calculated value of |u| is slightly higher for KZnF 3 /Cu 2+ (u = 13.5 pm) than that for K 2 ZnF 4 /Cu 2+ (|u| = 11 pm), |Δ| = ∼0.7 eV for K 2 ZnF 4 /Cu 2+16 is much higher than that for KZnF 3 /Cu 2+ , where Δ < 0.5 eV. 17 Furthermore, upon going from K 2 ZnF 4 /Cu 2+ to KCuF 3 , |u| grows by a factor of three, while the experimental |Δ| value increases only by a factor of 1.35 (Table 1).…”