H. S. Zhuo

Study of modified tgs crystals

Abstract Based on the relation between the structure and spontaneous polarization of TGS crystal, some modified TGS crystals have been grown by doping with aniline-family dipolar moleculars, inorganic acids and metal ions in the crystals. The effects of different dopants on growth habit and pyroelectric properties were investigated. The experimental results show that the pyroelectric figure of merit (p/e) of these new modified TGS-ATGSP and ATGSAs are one time higher than that of pure TGS crystal. The main approach of study on the modification of TGS crystal is also discussed in this paper.

Study on the pyroelectric properties of TGS-PVDF composites

Abstract TGS-PVDF composite has been prepared in our laboratory and its dielectric and pyroelectric properties were analyzed. The dielectric constants, dielectric losses and pyroelectric coefficients of this composite with different component proportions have been measured, and their variations with temperature were observed. In addition, the figure of merit M has also been calculated. The D* value of the pyroelectric devices made from this composite even reach (5–7) × 107 cm · Hz1/2 · W−1 . The results have shown that TGS-PVDF composite has bright prospects in applications as a pyroelectric composite material.

Growth mechanism of doped polar trigycine sulfate crystals

L-alanine and phosphoric acid doped triglycine sulfate (ATGSP) is a typical polar crystal. This crystal is quite different from the pure TGS crystal. The growth characterics of doped polar TGS crystals were revealed by measuring the growth rate, domain structure, hysteresis loops and X-ray topography in two polar ends of TGS and ATGSP crystals. The growth mechanism of doped TGS crystals is also discussed.

ADTGSP single crystal with high pyroelectric figure of merit

Abstract This paper reports the distribution coefficient of phosphoric acid in solid-liquid phases and the conditions for the stepwise synthesis of chemical materials of ADTGSP crystals. The transparent bulk ADTGSP crystals were grown by lowering temperature method. The pyroelectric, dielectric, ferroelectric properties of ADTGSP crystal were measured and it is found that this crystal possesses higher pyroelectric figure of merit than that of TGS and DTGS crystals.

Study of the inhomogeneity and domain structure of polar ATGSP crystals

Abstract ATGSP crystal is a typical polar material. The crystal growth rate, domain structure and some properties in the polar direction (±b, are quite different. The distribution of domain in the crystal has been investigated by decoration method. The parameters such as internal bias field in the different regions of the crystal were measured by hysteresis loop method. It is found that in the fast growth region (along +b axis), the bias field is low, the doping is inhomogeneous and some reverse domains exist in the crystal, while in the slow growth region (along - b, axis), the case is quite the opposite. Taking advantage of these growth characteristics and using directional growth technique, homogeneous doped and single domain crystals have been grown.

Study of pyroelectric properties of TGSe and DTGSe crystals

Abstract The problem of crystal craking has been solved by using of synthetic method with modified raw materials. Large TGSe and DTGSe single crystals with high qualities have been grown. Such parameters as pyroelectric coefficient, relative dielectric constant and loss tgδ have been measured. Meantimes, this paper also analyses the advantages and disadvantages as well as the prospect of these two crystals in their applications as pyroelectric materials.

Dielectric and pyroelectric properties of rapid growth TGS crystals

Abstract This paper reports the dielectric constant e, spontaneous polarization strength P8 and pyroelectric coefficient of TGS crystals grown at rates of 2 mm/day and 7 mm/day respectively at different temperatures. The results indicate that the e, P, and A, of the crystals grown at higher rates are larger than those of the crystals grown at normal rates. The maximum value of dielectric constant of the former is smaller than that of the latter near the curie point. The figures of merit of the rapid growth crystals are almost the same as those of the crystals grown at normal rates. Finally, the experimental results are discussed based on the influences of crystal defects on the crystal properties.

Rapid growth of ferroelectric tgs crystals

Abstract This paper reports the solution conditions and rapid growth results for TGS crystals. It is found that a solution with pH of 2.52 is the optimum one for the rapid growth of TGS crystals. By using a quick rotating impeller to enhance the convection, the growth rate of (010) face has reached 5 mm/day, and the cross section of (010) face is 40 mm × 40 mm.