ESR of the Cu2+: ZnZrF6x6H2O Jahn-Teller system in the short wavelength part of the millimeter range

Investigations of ESR spectra of Cu2+:ZnZrF6xH2O Jahn-Teller system are carried out at 47 and 140 GHz frequencies. The observed spectrum may be described in terms of model of three geometrically nonequivalent centres with rhombic g-tensor: gz=2.473±0.003, gx=2.095±0.005, gy=2.103±0.005, gy-gx=0.0084±0.0004. Angle between z axis of magnetic complexes and third order axis of γ=54±0.30 crystal is determined. Shift of transition region at H0 parallel to z in higher temperatures is detected at the increase of radiospectrometer frequency. The obtained results are discussed using several theoretical investigations. Height of barrier between absolute minima of Vφ=115 cm-1 adiabatic potential is evaluated