Relaxor ferroelectric single crystals Pb((Mg1/3Nb2/3)1-x Ti x )O3 (PMNT 100(1-x)/100x) were grown directly from melt by a modified Bridgman technique. The segregation during the growth of PMNT single crystals was studied by means of differential thermal analysis (TGA), thermogravimetric analysis (DTA), X-ray diffraction (XRD) and X-ray fluorescence analyzer (XRFA). The results show that PbTiO3 content increases throughout the crystal growth. The segregation coefficient is about 0.95 during the growth of PMNT 76/24 directly from melt. Therefore, the electric properties of PMNT single crystals vary even in the same boule. It was demonstrated that the homogeneity of PMNT single crystals can be improved by optimizing growth parameters, but it cannot be eliminated because of the effect of segregation during the crystal growth. We have recently improved the growth process of the modified Bridgman technique to increase the homogeneity of the crystals. Good-quality single crystals with a boule size of more than φ40×80 mm or 30×30×1 mm plates have been achieved. For PMNT 67/33 crystals, their coupling factors are k 33≈94% for the longitudinal mode, k 33 ′≈86% for the beam mode, and k t≈62% for the thickness mode, and they have the piezoelectric constant d 33=1500–3000 pC/N, and dielectric constant ε 33/ε 0=3500–5500.

Investigating the structure, modification, interaction, and function of biomolecules in their native cellular environment leads to physiologically relevant knowledge about their mechanisms, which will benefit drug discovery and design. In recent years, nuclear and electron magnetic resonance (NMR) spectroscopy has emerged as a useful tool for elucidating the structure and function of biomacromolecules, including proteins, nucleic acids, and carbohydrates in living cells at atomic resolution. In this review, we summarize the progress and future of in-cell NMR as it is applied to proteins, nucleic acids, and carbohydrates.

In the principle of optical crystallography and crystal symmetry, it is found that at room temperature, the 0.67 PMN-0.33 PT crystals near the morphotropic phase boundary composition present not only a rhombohedral 3m phase but also a monoclinic m phase with various angles of polarization rotation, the third ferroelectric phase in the PMN-PT solid solution system. The polarization rotation readily driven by composition suggests that it can be easily induced by electric field as well, thereby providing the structure base of the ultrahigh piezoelectric performance of 0.67 PMN-0.33 PT single crystals.