Effect of pressure on the resistivity of lead oxide-lead halide glasses

Resistivity behaviour of PbOPbX 2 (X=F,Cl) glasses has been investigated as a function of pressure at laboratory temperature. All PbOPbX 2 glasses undergo crystallization under pressure and the resistivities of crystallized samples are lower than the corresponding glasses. Transitions in PbOPbF 2 glasses exhibit a first order behaviour while transitions in PbOPbCl 2 glasses possess features of a continuous transition. The differences in the pressure behaviour of the two glass systems have been attributed to the differences in the ionic sizes of F − and Cl − ions and also to pressure induced modifications of PbO bonding.