Magnetic Resonance of Spin Clusters and Triplet Excitations in a Spin-Peierls Magnet with Impurities

Abstract

The magnetic resonance spectrum of spin clusters formed in spin-Peierls magnets in the vicinity of impurity ions was investigated. The observed temperature dependences of the effective g-factor and the linewidth of the electron spin resonance (ESR) in crystals of Cu(1-x)Ni(x)GeO(3) are described in the model of the exchange narrowing of the two-component spectrum with one component ascribed to spin clusters and exhibiting an anomalous value of the $g$-factor and the other related to triplet excitations. An estimation of the size of the suppressed dimerization region around the impurity ion is obtained (this region includes about 30 copper ions). The dependence of the effective g-factor and the ESR linewidth on the impurity concentration at low temperatures indicates the interaction of clusters.

9 pages, 9 figures, to be published in JETP v.120, July 2001

Cited by in corpus (5)

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• Paramagnetic and antiferromagnetic resonances in the diamagnetically diluted Haldane magnet PbNi2V2O8
• Separation of the magnetic phases at the Néel point in the diluted spin-Peierls magnet CuGeO3
• Influence of magnetic interaction between impurity and impurity-liberated spins on the magnetism in the doped Haldane chain compounds PbNi${}_{2-x${A}${}_x$V${}_2$O${}_8$ (A = Mg, Co)
• Formation of the S=1 paramagnetic centers in the bond-diluted spin-gap magnet