GLASS AND COMPOUNDS IN THE SYSTEM P4S4-AS 4S4-AS4SE4-P4SE4

Glas forming regions and glass temperatures of the system P4S4-As4S4-A s4Se4-P4Se4 have been determined by thermoanalytical and X-ray methods . In the whole system crystalline samples have been obtained by anneal ing. From the pure phases AS4S4 and P4Se4 broad regions of solid solut ions extend into the system. In the P4S4 corner the formation of A4B3 (A = P, As; B = S, Se) molecules is observed. As with A4B3 molecules, a stepwise substitution of P by As atoms, and of S by Se atoms is poss ible. All molecules of the series P4-nAsnS4 and AS4S4-nSen (n = 0, 1, 2, 3, 4) were detected by P-31 NMR and/or mass spectroscopy.