Glass structure, rigidity transitions and the intermediate phase in the ternary
Department of Electrical & Computer Engineering and Computer
Science University of Cincinnati - Cincinnati, OH 45221-0030, USA
2 Laboratoire de Physique Theorique des Liquides, Université Pierre et Marie Curie Tour 16, 4 Place Jussieu, 75252 Paris, Cedex 05, France
Accepted: 16 October 2000
The non-reversing heat flow, near in ternary glasses is examined by temperature-modulated differential scanning calorimetry. The term shows a deep minimum (which is almost zero) in the 0.09 < x < 0.14 range, identified with the intermediate phase, and an increase, both at low x (< 0.09) in the floppy phase and at high x (> 0.14) in the stressed rigid phase. Expressed in terms of mean coordination number, , the large width, , of the intermediate phase and its low onset value are shown to be consistent with the presence of units in addition to pyramidal and tetrahedral units in the stress-free backbone. The vanishing of in the intermediate phase is in harmony with the notion that the number of Lagrangian constraints/atom exhausts the three available degrees of freedom, and leaves the backbone in a mechanically stress-free state.
PACS: 61.43.Fs – Glasses / 63.50.+x – Vibrational states in disordered systems / 61.20.-p – Structure of liquids
© EDP Sciences, 2000