A contribution to the understanding of the polyamorphism situation in triphenyl phosphite

• Published in: Physical chemistry chemical physics : PCCP 2004-06, Vol.6 (12), p.3192-3199
• Main Authors: HEDOUX, Alain, GUINET, Yannick, DEROLLEZ, Patrick, HERNANDEZ, Olivier, LEFORT, Ronan, DESCAMPS, Marc
• Format: Article
• Language: English
• Subjects: Chemistry; Condensed Matter; Exact sciences and technology; General and physical chemistry; Materials Science; Physics
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/b401262c

Triphenyl phosphite (TPP) is now well known to exhibit an intriguing transformation of the supercooled liquid. The transformation was firstly interpreted as a first-order polyamorphic transition between the supercooled liquid and an apparently amorphous state different from the glass and the ordinary liquid, the so-called glacial state. In this paper, we describe and analyze, from experimental investigations (Raman spectroscopy, calorimetric measurements, X-ray and neutron diffraction), the transformation into the glacial state and the structural organization of this state. The latter is interpreted as a heavily nucleated state composed of nanocrystals of the stable crystalline phase embedded in the matrix of non-transformed supercooled liquid. The origin of the intriguing relative stability of this state could result in the combination of two phenomena: the time lag required to attain steady-state values of the nucleation rate (connected to the high viscosity of TPP), and a high nucleation rate in the temperature range where the growth rate is low. These results converge into a description of the glacial state as a mixed supercooled liquid/crystallites state, and then contradict recent claims that the glacial state of TPP is a homogeneous amorphous phase.