Phase transitions and transport properties in tetra-n-butylammonium iodide

A. A. Iskakova, N. B. Asanbaeva, K. B. Gerasimov, N. F. Uvarov, A. B. Slobodyuk, V. Ya Kavun

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

A remarkable feature of organic salts is easy reorientation of organic groups, especially in high-temperature phases. It would be expected that the reorientational motion of organic groups promotes also ion transport processes within the crystal structure. In this work thermal and transport properties of solid organic salt (n-C 4 H 9 ) 4 NI were investigated by methods of DSC, dilatometry, conductivity measurements and NMR spectroscopy. It was proposed that three low-temperature phases, II, III and IV, along to the high-temperature phase I appear in this salt after heat treatment. The conductivity and temperature stability range of the low-temperature phases depend on conditions of the heat treatment of the salt. Temperature intervals of stability of phases II and III considerably increases after prolonged heating in the melt. In parallel, the conductivity of all low-temperature phases increases in contrast to the conductivity of the phase I. These facts may be explained by the formation of extrinsic iodine vacancies as a result of the dissolution of tributylanine formed at partial thermal decomposition of the salt. According to 1 H NMR data, in high-temperature phase TBA cations are mobile. No information on anionic diffusion in this phase was obtained due to a low intensity of 127 I NMR spectra. The most mobile defects in low-temperature phases of (n-C 4 H 9 ) 4 NI seem to be iodine vacancies.

Original languageEnglish
Pages (from-to)26-30
Number of pages5
JournalSolid State Ionics
Volume336
DOIs
Publication statusPublished - 1 Aug 2019

Keywords

  • H and I NMR study
  • High-temperature disordered phase
  • Iodine vacancies
  • Ionic conductivity
  • Phase stability
  • Plastic crystals
  • Tetra-n-butylammonium iodide
  • Thermal decomposition
  • SOLID-STATE NMR
  • ROTATOR PHASE
  • ELECTRICAL-CONDUCTIVITY
  • X-RAY-DIFFRACTION
  • PERCHLORATE
  • H-1
  • MOTIONS
  • PLASTIC CRYSTAL PHASES
  • H-1 and I-127 NMR study
  • MAGNETIC-RESONANCE
  • ENTROPY

Fingerprint Dive into the research topics of 'Phase transitions and transport properties in tetra-n-butylammonium iodide'. Together they form a unique fingerprint.

Cite this