127I Pure Quadrupole Resonance Spectrum of Orthoperiodic acid, H5IO6

Abstract

The NQR-spectrum of 127I in orthoperiodic acid, Η5ΙΟ6 , has been studied on powder samples in the temperature range 77 Κ ≦ Τ ≦ 398 Κ. The resonance frequencies ν1 of the transition m(±3/2) ⇄ m (±1/2) are 45.248±0.005 MHz (77 K) and 44.976 ± 0.005 MHz (296 K). For the⇄ transition m(±5/2) ⇄ m(±3/2) the resonance frequencies v2 are 83.478±0.005 MHz (77 K) and 83.960 ± 0.005 MHz (296 K). The corresponding quadrupole coupling constants, e2 q Q/h, are 282.977±0.005 MHz (296 K), and 281.892±0.005 MHz (77 K). The asymmetry parameters η have been determined as 0.2372±0.0001 (296 K), and 0.2580±0.0001 (77 K). A small change of 0.4% for e2 qQ/h is accompanied by a rather large change of 21% for η within the temperature range investigated. e2 q Q/h=f(T) shows a maximum at ~ 313 K. No evidence of phase transition has been observed by NQR spectroscopy between 77 K and 398 K.