In-situ Raman spectroscopy unveils metastable crystallization in lead metasilicate glass

Is the structural relaxation of glasses controlled by equilibrium shear viscosity?

“…We used samples of a PS glass previously obtained in our laboratory. The melting and casting procedure was described in reference, 48 and other studies on this particular batch of PS glass have been reported in references 50,51 . The glass‐transition temperature was measured by the onset of the glass–SCL transition of the differential scanning calorimetry (DSC, Netzsch 404 equipment) at a heating rate of 10 K min −1 , = 681 K. This particular composition was chosen because experimental values of isostructural viscosity 49 are available.…”

Vibrational Raman modes of alamosite (PbSiO3): Combining density functional theory calculations and in situ temperature experiments

“…13 Another possibility arises from the crystallization of the isochemical glass, from which alamosite is the stable form. 13,14 Indeed, a recent in situ synchrotron X-ray diffraction investigation, performed up to 973 K, reported high stability of the monoclinic structure and lattice expansion without deformation in the angles of the unit cell axes, further deriving the thermal expansion coefficients and bulk modulus for this structure. 15 The Raman spectrum of the alamosite at room conditions, 4,5 as a fingerprint, is well-known and was used in a previous contribution of ours as a basis for qualitatively describing the crystallization pathways from the isochemical glass toward alamosite upon heat treatment.…”

Normal to abnormal behavior of PbSiO3 glass: A vibrational spectroscopy investigation under high-pressure

“…The average compositions of the glass batches (Table 1) are accurate to the nominal lead to silica proportion within an estimated uncertainty of  0.5 mol.%. The microscopic PS specimens compressed in the diamond anvil cell (DAC) are from the same batch as in these works [16,[18][19][20][21], compressed as-prepared. The macroscopic PS sample submitted to high-pressure in the Belt press is from a distinct batch, cut to guarantee geometric requirements, i.e.…”