39K nuclear magnetic resonance in a KHSO4 single crystal

Abstract

The 39K NMR in a KHSO4 single crystal grown by the slow evaporationmethod was investigated by employing a Bruker FT NMR spectrometer, and the39K quadrupole coupling was determined from the angular dependences ofthe four 39K±1/2↔∓1/2 central NMRtransitions. There are two sets of crystallographically inequivalent K+ions: K(1) and K(2). From these angular dependences, all lead to differentvalues for the quadrupole coupling constant and asymmetry parameter:e2qQ/h = 1.06±0.07 MHz, η = 0.58±0.05 for the K(1) ion, ande2qQ/h = 1.45±0.07 MHz, η = 0.85±0.05 for the K(2) ion. TheEFG tensors of K(1) and K(2) are asymmetric and the orientations of theprincipal axes of the EFG tensors do not coincide for the K(1) and K(2)sites. The K(1) ions surrounded by nine oxygen atoms are high in symmetry,while K(2) ions surrounded by nine oxygen atoms show low symmetry.