A neutron diffraction study of the phase transition of fully deuterated triglycine sulphate (ND2CD2COOD)3.D2SO4. Issue 3 (13th March 2013)

• Record Type: Journal Article
• Authors: Hudspeth, J. M.; Goossens, D. J.; Gutmann, M. J.; Studer, A. J.
• Is Part Of: Crystal research and technology. Volume 48:Issue 3(2013:Mar.)
• Page Start: 169
• Page End: 180
• Publication Date: 2013-03-13
• Subjects: Crystallography -- Periodicals; 548
• DOI: 10.1002/crat.201300061
• Languages: English
• ISSNs: 0232-1300

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Using neutron single crystal and powder diffraction, the first thorough investigation of the structure of fully deuterated triglycine sulphate, (ND₂CD₂COOD)₃.D₂SO₄ is presented, including its evolution with <italic>T</italic>, through its structural phase transition. This includes new precise structural parameters determined at several key temperatures above and below <italic>T</italic>_{<italic>C</italic>} using single crystal diffraction, and for the first time a parametric study has been undertaken over a wide temperature range — from 4 to 500 K in 2 K steps. It was found that fully deuterated TGS shows a structure consistent with hydrogenous TGS and partially deuterated TGS. The evolution of several key hydrogen bond lengths suggests that weakening of the H‐bond network with <italic>T</italic> is crucial in decoupling the polarising glycine molecules from the other glycines and allowing the long‐range ferroelectric order to break down. A new parameterisation of the phase transition is demonstrated. Contrary to results of physical properties measurements, there is no evidence of a second low temperature phase transition in TGS – no low temperature anomalies were observed in the crystal structure.</p> </abstract>