Department of Physics, National Technical University of Athens, Athens, Greece.
J Phys Condens Matter. 2010 May 19;22(19):195103. doi: 10.1088/0953-8984/22/19/195103. Epub 2010 Apr 16.
Raman scattering and differential scanning calorimetry (DSC) measurements have been carried out on four mixed tellurium-zinc oxide (TeO(2))(1 - x)(ZnO)(x) (x = 0.1, 0.2, 0.3, 0.4) glasses under variable temperature, with particular attention being given to the respective glass transition region. From the DSC measurements, the glass transition temperature T(g) has been determined for each glass, showing a monotonous decrease of T(g) with increasing ZnO content. The Raman study is focused on the low-frequency band of the glasses, the so-called boson peak (BP), whose frequency undergoes an abrupt decrease at a temperature T(d) very close to the respective T(g) values obtained by DSC. These results show that the BP is highly sensitive to dynamical effects over the glass transition and provides a means for an equally reliable (to DSC) determination of T(g) in tellurite glasses and other network glasses. The discontinuous temperature dependence of the BP frequency at the glass transition, along with the absence of such a behaviour by the high-frequency Raman bands (due to local atomic vibrations), indicates that marked changes of the medium range order (MRO) occur at T(g) and confirms the correlation between the BP and the MRO of glasses.
变温条件下对四个混合碲-氧化锌（TeO(2))(1 - x)(ZnO)(x) (x = 0.1, 0.2, 0.3, 0.4) 玻璃进行了拉曼散射和差示扫描量热法（DSC）测量，特别关注各自的玻璃化转变区域。通过 DSC 测量，确定了每种玻璃的玻璃化转变温度 T(g)，结果表明 T(g)随 ZnO 含量的增加呈单调下降。拉曼研究集中在玻璃的低频带，即所谓的玻色峰（BP），其频率在温度 T(d)处急剧下降，该温度非常接近 DSC 得到的各自 T(g)值。这些结果表明，BP 对玻璃转变过程中的动力学效应非常敏感，并为确定碲酸盐玻璃和其他网络玻璃的 T(g)提供了一种同样可靠的（与 DSC 相比）方法。BP 频率在玻璃转变处的不连续温度依赖性，以及高频拉曼带（由于局部原子振动）不存在这种行为，表明在 T(g)处发生了明显的中程有序（MRO）变化，并证实了 BP 与玻璃的 MRO 之间的相关性。
