Ionic motion and Disordered Structure in the Rotator Phase of Butylammonium Chloride Studied by Temperature Dependences of ³⁵Cl and ²H NMR

Abstract

Abstract Temperature dependences of 35 Cl and 2 H quadrupole coupling constants and 35 Cl NMR spin-lat­tice relaxation times in polycrystalline samples were measured in the rotator phase of the butylammonium chlorides C 4 H 9 NH 3 C 1 and C 4 H 9 ND 3 C 1 , obtainable above the phase transition temperature of 241 K. A rapid decrease o f the quadrupole coupling constants of both nuclei upon heating is attributed to increasing dynamic disorder formed around the polar head. The presence of self-diffussion of Cl - ions was revealed from the spin-spin relaxation time and resonance line-width in single crystals, and confirmed by measuring the dc electrical conductivity.