High-resolution powder neutron diffraction data (HRPD, ISIS Facility, U.K.) were collected on (H3O)Zr2(PO4)3 between 4 and 300 K. In the range 175-180 K, a ferroelastic first-order phase transition from the rhombohedral R3̄c NASICON structure to a monoclinic distorted one was discovered. Rietveld structure refinements were performed at 300 K (a = 8.74848(3), c = 23.7598(1) Å) and 4.5 K (space group C2/c or Cc, a = 15.0663(1), b = 8.7878(1), c = 9.3611(1) Å, β = 122.498(1)°). At RT, the hydronium ion H3O+ is pyramidal disordered over two inversion-related configurations. At LT, H3O+ becomes nearly planar, with two H atoms ordered and hydrogen-bonded to neighboring oxygens, and the third H atom disordered over two close positions with 2/3 and 1/3 statistical occupancies. Relations with the structural features of hydronium in other structures and the nature of order-disorder are discussed. An atomistic mechanism for proton conductivity is proposed.
Catti, M., & Ibberson, R.M. (2002). Order-disorder of the hydronium ion and low-temperature phase transition of (H3O)Zr-2(PO4)(3) NASICON by neutron diffraction. JOURNAL OF PHYSICAL CHEMISTRY. B, CONDENSED MATTER, MATERIALS, SURFACES, INTERFACES & BIOPHYSICAL, 106(46), 11916-11921 [10.1021/jp021424d].
Citazione: | Catti, M., & Ibberson, R.M. (2002). Order-disorder of the hydronium ion and low-temperature phase transition of (H3O)Zr-2(PO4)(3) NASICON by neutron diffraction. JOURNAL OF PHYSICAL CHEMISTRY. B, CONDENSED MATTER, MATERIALS, SURFACES, INTERFACES & BIOPHYSICAL, 106(46), 11916-11921 [10.1021/jp021424d]. | |
Tipo: | Articolo in rivista - Articolo scientifico | |
Carattere della pubblicazione: | Scientifica | |
Titolo: | Order-disorder of the hydronium ion and low-temperature phase transition of (H3O)Zr-2(PO4)(3) NASICON by neutron diffraction | |
Autori: | Catti, M; Ibberson, RM | |
Autori: | ||
Data di pubblicazione: | 21-nov-2002 | |
Lingua: | English | |
Rivista: | JOURNAL OF PHYSICAL CHEMISTRY. B, CONDENSED MATTER, MATERIALS, SURFACES, INTERFACES & BIOPHYSICAL | |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1021/jp021424d | |
Appare nelle tipologie: | 01 - Articolo su rivista |