The NMR study of ionic motions and conductivity mechanisms in protonic conductors MHSeO₄and M₃H(AO₄)₂

Structural Phase Transitions and Crystal Structure for Na3D(SO4)2 Crystals at Room Temperature

“…The shift of the peak temperature in the heating and cooling curves is also found to be about 14 K downward on substitution of deuterium in the sample crystal. The peak temperature (555.2 K) obtained from the heating curve of the proton compound differs greatly from the phase transition temperature (533 K) found in NMR measurements [8]. However, the peak temperature (540.2 K) from the cooling curve is close to the transition temperature.…”

“…The high-and low-temperature phase transitions have been found at 533 K in NMR experiments and at 178(3) K in differential scanning calorimetry (DSC) measurements [8,9]. The crystal structures of Na 3 H(SO 4 ) 2 at room temperature and at 139 K in the low-temperature phase are found to be monoclinic with space group P2 1 /c and triclinic P1, respectively [9 to 11].…”

Synthesis of ammonia directly from air and water at ambient temperature and pressure

“…The high ionic conductivity is believed due to NH 4 + ions but proton conduction cannot be ruled out. It has been reported that some inorganic ammonium salts such as (NH 4 ) 3 H(SeO 4 ) 2 exhibit proton conduction3637. Therefore the NH 4 + -form Nafion may exhibit a certain level of proton conduction which can be used for continuous synthesis of ammonia.…”

Dielectric relaxation of CsHSeO4 above room temperature

“…The CsHSeO 4 is a solid electrolyte that exhibits a superionic protonic conduction behavior above T c = 401 K [4][5][6][7]. The first order phase transition is accompanied by a strong conductivity increase, by four orders of magnitude, which essentially originates from proton diffusion [8][9][10][11].…”