多晶铌酸钾钠在高压下的声学和弹性性质研究  

Acoustic and Elastic Properties of Polycrystalline Potassium Sodium Niobate under High Pressures

作　　者：肖礼康 冯秋 房雷鸣[3] 周章洋 熊政伟[2] 蓝江河[1] 杨佳[4] 刘艺[4] 高志鹏 XIAO Likang;FENG Qiu;FANG Leiming;ZHOU Zhangyang;XIONG Zhengwei;LAN Jianghe;YANG Jia;LIU Yi;GAO Zhipeng(School of Electronic Science and Engineering,University of Electronic Science and Technology of China,Chengdu 611731,Sichuan,China;School of Mathematics and Physics,Southwest University of Science and Technology,Mianyang 621010,Sichuan,China;Institute of Nuclear Physics and Chemistry,China Academy of Engineering Physics,Mianyang 621999,Sichuan,China;Institute of Fluid Physics,China Academy of Engineering Physics,Mianyang 621999,Sichuan,China)

机构地区：[1]电子科技大学电子科学与工程学院,四川成都611731 [2]西南科技大学数理学院,四川绵阳621010 [3]中国工程物理研究院核物理与化学研究所,四川绵阳621999 [4]中国工程物理研究院流体物理研究所,四川绵阳621999

出　　处：《高压物理学报》2023年第6期57-68,共12页Chinese Journal of High Pressure Physics

基　　金：国家自然科学基金委-中国工程物理研究院NSAF联合基金(U2230119);四川省自然科学基金(2022NSFSC0333);四川省杰出青年基金(22JCQN0005)。

摘　　要：在压力和温度分别为10 GPa和1050℃的条件下制备了Na_(0.5)K_(0.5)NbO_(3)陶瓷样品,采用超声干涉法测量了样品在不同静水压力下的压缩波速和剪切波速。通过三阶有限应变状态方程拟合,获得了多晶Na_(0.5)K_(0.5)NbO_(3)的体积模量(172.6 GPa)和剪切模量(54.6 GPa)及其压力依赖性。研究发现,样品的杨氏模量随着压力的升高而增大。基于弹性模量数据,得到样品的泊松比为0.342,表明材料具有延展性,但在高压下展现出脆性。随着压力的升高,维氏硬度和断裂韧性均增强;通过经验模型,得到陶瓷样品的维氏硬度为2.40 GPa,断裂韧性为2.33 MPa·m^(1/2)。基于弹性波速度和密度数据,推导出Na_(0.5)K_(0.5)NbO_(3)陶瓷的德拜温度为513.1 K,Grüneisen常数γ为2.113。这些结果为评估Na_(0.5)K_(0.5)NbO_(3)在高压下的声学性质和弹性相关的综合性质提供了科学依据,同时为Na_(0.5)K_(0.5)NbO_(3)在高压下的工程应用提供了参考。Polycrystalline Na_(0.5)K_(0.5)NbO_(3)ceramics were prepared under the condition of 10 GPa and 1050℃.The compression and shear wave velocities of the samples under various hydrostatic pressures were measured using ultrasonic interferometry.By fitting the third-order finite strain state equation,the bulk and shear moduli of polycrystalline Na_(0.5)K_(0.5)NbO_(3)and their pressure dependency were determined as 172.6 GPa,54.6 GPa,0.3 and 2.1,respectively.The sample shows a positive pressure dependence of Young’s modulus.Based on the elastic modulus data,the Poisson’s ratio was obtained as 0.342,indicating that the material was ductile and shows brittleness under high pressure.The Vickers hardness and fracture toughness also show positive pressure dependence.Using the empirical models,the Vickers hardness and fracture toughness of the ceramics were obtained as 2.40 GPa and 2.33 MPa·m^(1/2).Meanwhile,based on the elastic wave velocity and density data,the Debye temperature(513.1 K)and the Grüneisen constant(2.113)of Na_(0.5)K_(0.5)NbO_(3)ceramics were derived.Our results provide an experimental reference for evaluating the acoustic and elastic-related comprehensive properties of Na_(0.5)K_(0.5)NbO_(3)under high pressure,and a foundation for its engineering applications under extreme high-pressure conditions as well.

关 键 词：Na_(0.5)K_(0.5)NbO_(3) 高压 声速 弹性 硬度 断裂韧性 

分 类 号：O521.2[理学—高压高温物理]