1H and 19F NMR relaxation time studies in (NH4)2ZrF6 superionic conductor

Abstract

Abstract. 1 H and 19 F spin lattice relaxation times in polycrystalline diammonium hexafluorozirconate have been measured in the temperature range of 10 400 K to elucidate the molecular motion of both cation and anion. Interesting features such as translational diffusion at higher temperatures, molecular reorientational motion of both cation and anion groups at intermediate temperatures and quantum rotational tunneling of the ammonium group at lower temperatures have been observed. Nuclear magnetic resonance (NMR) relaxation time results correlate well with the NMR second moment and conductivity studies reported earlier.

1H NMR study of internal motions and quantum rotational tunneling in (CH3)4NGeCl3

“…[14] The temperature of the sample is controlled using homemade gas flow cryostat and the temperature at the sample is measured using a Pt 100 sensor. Second moment is calculated from the derivative of the absorption signal recorded using lock-in detection.…”

Ion mobility and phase transitions in heptafluorodiantimonates(III) Cs (1−x) (NH 4 ) x Sb 2 F 7 and K 0.4 Rb 0.6 Sb 2 F 7 according to NMR and DSC data

“…The similar situation is characteristic for the compound Cs 0.9 (NH 4 ) 0.1 Sb 2 F 7 . It should be noted that the possibility of diffusion emergence of NH 4 + ions in the ammonium fluoroantimonates(III) NH 4 Sb 2 F 7 , (NH 4 ) 2 Sb 2 F 11 , (NH 4 ) 3 Sb 4 F 15 , and NH 4 SbF 4 was considered, for instance, in [21], whereas for the ammonium fluorozirconates (NH 4 ) 2 ZrF 6 , (NH 4 ) 3 ZrF 7 , and (NH 4 ) 6 LiZr 4 F 23 it was confirmed in [9,[22][23][24][25]. According to 19 F NMR data, the activation of local mobility in the fluoride sublattice starts above 360 K for the sample Cs 0.8 (NH 4 ) 0.2 Sb 2 F 7 and above 330 K for the sample Cs 0.4 (NH 4 ) 0.6 Sb 2 F 7 .…”

STRUCTURE OF POLYMORPHS OF COMPLEX ZIRCONIUM AND HAFNIUM FLUORIDES WITH THE 4-AMINO-1,2,4-TRIAZOLIUM CATION: (C2H5N4)2MF6 (M = Zr, Hf, ZrxHf1-x)

“…ɂɧɬɟɪɟɫ ɤ ɤɨɦɩɥɟɤɫɧɵɦ ɮɬɨɪɢɞɚɦ ɰɢɪɤɨɧɢɹ ɢ ɝɚɮɧɢɹ ɨɛɭɫɥɨɜɥɟɧ ɨɛɧɚɪɭɠɟɧɢɟɦ ɜɨ ɦɧɨɝɢɯ ɫɨɟɞɢɧɟɧɢɹɯ ɷɬɨɝɨ ɤɥɚɫɫɚ ɰɟɧɧɵɯ ɮɭɧɤɰɢɨɧɚɥɶɧɵɯ ɫɜɨɣɫɬɜ, ɱɬɨ ɩɨɡɜɨɥɢɥɨ ɩɪɟɞɥɨɠɢɬɶ ɢɯ ɩɪɢɦɟɧɟɧɢɟ ɜ ɤɚɱɟɫɬɜɟ ɢɨɧɧɵɯ ɩɪɨɜɨɞɧɢɤɨɜ [1][2][3], ɫɟɝɧɟɬɨɷɥɟɤɬɪɢɤɨɜ [ 4 ], ɥɸɦɢɧɨɮɨɪɨɜ [ 5,6 ]. ɋɨɡɞɚɧɧɵɟ ɧɚ ɨɫɧɨɜɟ ɮɬɨɪɢɞɧɵɯ ɫɨɟɞɢɧɟɧɢɣ ɰɢɪɤɨɧɢɹ ɮɬɨɪɨɰɢɪɤɨɧɚɬɧɵɟ ɫɬɟɤɥɚ ɛɥɚɝɨɞɚɪɹ ɢɯ ɜɵɫɨɤɨɣ ɨɩɬɢɱɟɫɤɨɣ ɩɪɨɡɪɚɱɧɨɫɬɢ ɧɚɲɥɢ ɩɪɢɦɟɧɟɧɢɟ ɞɥɹ ɫɨɡɞɚɧɢɹ ɨɩɬɢɱɟɫɤɢɯ ɬɟɥɟɤɨɦɦɭɧɢɤɚɰɢɨɧɧɵɯ ɭɫɬɪɨɣɫɬɜ, ɨɩɬɢɱɟɫɤɢɯ ɜɨɥɨɤɨɧ, ɨɩɬɢɱɟɫɤɢɯ ɭɫɢɥɢɬɟɥɟɣ ɢ ɞɚɬɱɢɤɨɜ [ 7 ].…”