Abstract The present work reports the growth and characterization of single crystals of pure triglycine sulphate (TGS) and maleic acid doped triglycine sulfate (MA-TGS). Both the crystals were grown by conventional slow evaporation solution technique. The crystal structure, composition and morphology of both pure TGS and MA-TGS crystals were studied using single crystal and powder X-ray diffraction, scanning electron microscope, and CHNS analysis. The results revealed monoclinic crystal system for both the crystals with space group P21. Thermal stability and melting point of the grown crystals were determined by employing thermogravimetric and differential thermal analysis (TG-DTA) technique. The dielectric study showed an increase in Curie temperature along with a decrease in maximum permittivity due to MA doping. Enhanced piezoelectric, ferroelectric and mechanical properties were obtained for the doped crystal. The value of piezoelectric charge coefficient, d22 was estimated from ‘Displacement-Voltage (D-V)’ butterfly curves and was observed to increase from 56.23 pm/V for pure TGS single crystal to 72.02 pm/V for MA-TGS single crystal. An increase in the ferroelectric parameters (spontaneous and remanent polarizations) was observed for doped TGS crystal. Also, the value of true-remanent polarization was determined using remanent hysteresis task for MA-TGS crystal. Mechanical stability of grown crystals was examined using the nanoindentation technique and various parameters such as the hardness, stiffness and Young’s modulus were evaluated. Nanoindentation results revealed that both the crystals have a greater capability to withstand deformation caused by applying various loads. However, the mechanical strength of MA-TGS crystal was observed to be better than that of pure TGS crystal. Comparative structural, ferroelectric, piezoelectric and mechanical studies provide useful scientific information of an important class of TGS crystals.

中文翻译：

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使用纳米压痕技术对压电/铁电马来酸掺杂的三甘氨酸硫酸盐单晶进行力学研究

摘要 目前的工作报告了纯硫酸三甘氨酸 (TGS) 和马来酸掺杂的硫酸三甘氨酸 (MA-TGS) 单晶的生长和表征。两种晶体都是通过传统的缓慢蒸发溶液技术生长的。使用单晶和粉末 X 射线衍射、扫描电子显微镜和 CHNS 分析研究了纯 TGS 和 MA-TGS 晶体的晶体结构、组成和形貌。结果表明，空间群为P21的晶体均为单斜晶系。通过使用热重和差热分析（​​TG-DTA）技术确定生长晶体的热稳定性和熔点。介电研究表明，由于 MA 掺杂，居里温度升高，同时最大介电常数降低。增强型压电，获得掺杂晶体的铁电和机械性能。压电电荷系数值 d22 是根据“位移-电压 (DV)”蝴蝶曲线估算的，观察到从纯 TGS 单晶的 56.23 pm/V 增加到 MA-TGS 单晶的 72.02 pm/V。对于掺杂的 TGS 晶体，观察到铁电参数（自发极化和剩余极化）的增加。此外，真正的剩余极化值是使用 MA-TGS 晶体的剩余磁滞任务确定的。使用纳米压痕技术检查生长晶体的机械稳定性，并评估各种参数，例如硬度、刚度和杨氏模量。纳米压痕结果表明，这两种晶体都具有更大的承受因施加各种载荷而引起的变形的能力。然而，观察到 MA-TGS 晶体的机械强度优于纯 TGS 晶体。比较结构、铁电、压电和机械研究为一类重要的 TGS 晶体提供了有用的科学信息。