Vibronic Effects in EPR Spectra of (NH_{4})_{2}Cu(BeF_{4})_{2}·6H_{2}0 Single Crystal

• Authors: S. Hoffmann , M. Gomółka-Marciniak
• Languages of publication: EN

Abstracts

EN

Angular variations of the g-factors and linewidth value were recorded at X-band, at room temperature, and at 77 K. The temperature dependence of the g-factors was measured along the principal g-tensor axes in the temperature range from 4.2 K to 300 K. The rigid lattice g-factors at 4.2 K are: g_{z} = 2.428, g_{y} = 2.138, and g_{x} = 2.058. The g_{x} value very slowly increases linearly on heating, whereas g_{z} and g_{y} nonlinearly tend towards their average value. This is a typical behaviour of Cu(II) EPR in Tutton salt crystals, however the g(T) dependence is much less pronounced in (NH_{4})_{2}Cu(BeF_{4})_{2}·6H_{2}0 as compared to the Cu(II) doped salts. The results are described in terms of the two vibronic coupling models of the strong Jahn-Teller effect. It is shown that the models are not adequate to describe the vibronic g-factor behaviour in paramagnetic Cu(II) crystals which is attributed to the cooperative Jahn-Teller effect existing in these crystals.

Keywords

EN

76.30.-v; 71.70.Ej

Discipline

• 71.70.Ej: Spin-orbit coupling, Zeeman and Stark splitting, Jahn-Teller effect
• 76.30.-v: Electron paramagnetic resonance and relaxation(see also 33.35.+r Electron resonance and relaxation in atomic and molecular physics; 87.80.Lg Magnetic and paramagnetic resonance in biological physics)

• Publisher: Institute of Physics, Polish Academy of Sciences
• Journal: Acta Physica Polonica A
• Year: 1993
• Volume: 83
• Issue: 6
• Pages: 817-830

Dates

published

1993-06

received

1993-03-04

(unknown)

1993-04-06

Contributors

author

S. Hoffmann

• Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17/19, 60-179 Poznań, Poland

author

M. Gomółka-Marciniak

• Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17/19, 60-179 Poznań, Poland

Identifiers

DOI

10.12693/APhysPolA.83.817