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Broad infrared emissions at 1131, 1107 and 1291 nm were observed in the bismuth doped aluminosilicate glasses under 532, 690 and 808 nm excitation respectively. The origin of the broadband infrared luminescence was investigated in the aluminosilicate glasses. Based on the energy matching conditions, it is suggested that the infrared luminescence centres might be Bi1+ ions and BiO molecules. The broadband infrared luminescent characteristics of the glasses indicate that they are promising for broadband optical fibre amplifiers and tunable lasers.

The diffuse phase transition in the polycrystal ferroelectrics Pb(Mgl/3Nb2/3)O3 and Pb(Nil/3Nb2/3)O, has been investigated under pressure up to 14kb. With increasing pressure p, diffuse factor u increase linearly, Curie-Weiss constant C and average Curie temperature T av decrease linearly. The phase transition becomes more diffused with increasing p. The ⟨E⟩ ∼ T curve can be explained in terms of the statistical model for diffuse phase transition. Using Martirena and Burfoot's experimental formula where T m is a temperature where e has the maximum in the ⟨e⟩ ∼ T curve, m and B are constants, the effect of pressure on the diffuse phase transition of the ferroelectrics Pb(Mg1/3Nb2/3)O, and Pb(Ni1/3Nb2/3)O3 can be analysed. Analogically, using the formula The pressure dependence of e at the various temperatures is shown.