1.
J Phys Condens Matter
; 29(36): 365401, 2017 Sep 13.
Artigo
em Inglês
| MEDLINE
| ID: mdl-28635620
RESUMO
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 (T N ≈ 7 K) excludes a paraelectric to antiferroelectric phase transition. Upon the 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 proton transfer and the compression of the short hydrogen bond length.