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Nanocrystalline (Pb0.95−xCa0.05Lax)Ti1−x/4O3 (PCLT) powders were prepared by the sol–gel technique. Doping-induced or grain size-induced structure phase transition was investigated by using Raman scattering and x-ray diffraction for the PCLT system. Experimental results show that the soft phonon mode E(TO1) displays a decrease in frequency but an increase in linewidth with increasing concentration of La. A discontinuous behavior of the phonon energy is associated with a phase transition from a ferroelectric tetragonal to a paraelectric cubic phase, and occurs at a morphotropic phase boundary of x≈0.30 for grain sizes being 20 nm. The dependence of Raman phonon modes on the size of particles has been analyzed for nanocrystalline (Pb0.88Ca0.04La0.08)Ti0.98O3 with grain sizes of 10–60 nm and a grain size-induced phase transition is observed for sizes below 14 nm.

This paper focuses on the function between the internal friction and frequency in soft matters. It attempts to prove that the shear wave can interact with microstructure units of certain sizes in soft matters. The specimen used in our experiment is glutin. Using the apparatus 1 developed by ourselves, we get the frequency spectrum of glutin, and point out that the spectrum is an inherent physical property of the substance.