Premium
Cluster of four superexchange‐coupled Cu 2+ ions in copper‐doped triglycine fluoroberyllate. A theoretical interpretation of the EPR spectrum
Author(s) -
Kurzyńaski M.,
Kowalewski L.
Publication year - 1975
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2220680128
Subject(s) - superexchange , electron paramagnetic resonance , chemistry , ion , anisotropy , copper , cluster (spacecraft) , condensed matter physics , isotropy , ground state , degenerate energy levels , crystallography , physics , atomic physics , nuclear magnetic resonance , quantum mechanics , organic chemistry , computer science , programming language
The unusual EPR spectrum of copper‐doped triglycine fluoroberyllate is shown to originate in large complcx molecules of the hypothetical formula [Cu 2+ ·(NH 2 CH 2 COO − ) 2 ·H 2 BeF 4 ] 4 , built into the distorted host lattice. Superexchange couplings of Cu 2+ ions in the cluster through CuFBeFCu paths are discussed. The isotropic superexchange interactions split the 16‐fold degenerate ground crystal state of the four Cu 2+ ions into multiplets the further splitting of which, originated by anisotropic interactions, can be described in terms of effective spin Hamiltonians with S = 2 and 1. The observed spectrum is attributed to transitions within the quintet and one of the triplets. By second‐order perturbation procedure, the phenomenological parameters of the effective spin Hamiltonians are expressed in terms of parameters directly describing anisotropic as well as isotropic superexchange interactions in the cluster. The magnitudes of these interactions are thus determined from experimental data.