Abstract
An anomalous increase in the real part of dielectric response is observed in Mn0.5Fe0.5AlPO4(OH)2H2O while cooling to ~70 K. This is addressed to field-induced proton dynamics in a short hydrogen bond of 2.480(3) Å. The absence of discontinuities in heat capacity curves above the Néel temperature (TN ≈ 7 K) excludes a paraelectric to antiferroelectric phase transition. Upon application of mild hydrostatic pressures below 1.6 GPa, the maximum in the dielectric response is shifted from 70 K to lower temperatures near ~2 K. This explains a narrow correlation between the proton transfer and the compression of the short hydrogen bond length.
Item Type: | Journal article |
---|---|
Form of publication: | Publisher's Version |
Keywords: | Proton motion; Hopping polarisation; Short hydrogen bonds; Phosphatic oxyhydroxides; Eosphorite-childrenite-series |
Faculties: | Geosciences > Department of Earth and Environmental Sciences > Crystallography and Materials Science |
Subjects: | 500 Science > 500 Science 500 Science > 530 Physics 500 Science > 550 Earth sciences and geology |
ISSN: | 0953-8984 |
Language: | English |
Item ID: | 40154 |
Date Deposited: | 07. Aug 2017, 10:00 |
Last Modified: | 04. Nov 2020, 13:17 |