Anomalous dielectric response of short hydrogen bonds under pressure

Röska, Benedikt; Park, Sohyun; Yoshimori, Yusuke; Kimura, Kenta und Kimura, Tsuyoshi (4. August 2017): Anomalous dielectric response of short hydrogen bonds under pressure. The case of (Mn,Fe)2+AlPO4(OH)2H2O. In: Journal of physics: Condensed matter, Bd. 29, Nr. 36, 365401

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.

• Dokumententyp: Zeitschriftenartikel
• Publikationsform: Publisher's Version
• Keywords: Proton motion; Hopping polarisation; Short hydrogen bonds; Phosphatic oxyhydroxides; Eosphorite-childrenite-series
• Fakultät: Geowissenschaften > Department für Geo- und Umweltwissenschaften > Kristallographie und Materialwissenschaft
• Themengebiete: 500 Naturwissenschaften und Mathematik > 500 Naturwissenschaften ; 500 Naturwissenschaften und Mathematik > 530 Physik ; 500 Naturwissenschaften und Mathematik > 550 Geowissenschaften, Geologie
• ISSN: 0953-8984
• Sprache: Englisch