Original scientific paper

A Multiple Thermal Analysis of Ammonium Heptamolybdate Tetrahydrate

Mladen Topić ; Laboratory for Solid State Chemistry, »Ruaer Boskovic« InsPitute, 41001 Zagreb, P.O. Box 1016, Croatia, Yugoslavia
Andreja Moguš-Milanković ; Laboratory for Solid State Chemistry, »Ruaer Boskovic« InsPitute, 41001 Zagreb, P.O. Box 1016, Croatia, Yugoslavia

Abstract

Crystalline powder of ammonium heiptamolybdate tetrahydrate
(AHM) was studied by use of thermally stimulated charge
(TSC), differential thermal analysis (DTA), permittivity and
dielectric loss measurements in the range from 113 K to 300 K.
TSC performed on d.c. poied samples resulted in a homocharge
release with a discontinuity in .the v.icinity of 200 K.
TSC carr ied out in heating-cooling cycles did not confirm a
recent assumption of ferroelectric activity in AHM powder. TSC
of the unpoled samples showed a pea;k at (280 ± 10) K indicating
a phase transition. A similar result was obtained by DTA
showing an endothermic peak at (260±4) K. e(T) and tg o(T)
increased substantially above 200 K because o which is proibably the reason fo!l"' the ihomocharge storage in
Poled samples.

Keywords

Hrčak ID:

194172

URI

https://hrcak.srce.hr/194172

Publication date:

15.2.1984.

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