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1.
从Anderson-Grüneisen参数定义式和热膨胀系数定义式出发,根据Tallon的普遍化理论,推导出了一个用于计算弹性常数的理论模型,用所得到的理论模型分别计算了MgO和Cu两种固体材料的弹性常数C_(11)、C_(12)和C_(44)随压强以及温度变化的理论数值,并将理论计算结果与Kumar模型计算结果以及相关实验数据进行了比较,对所得到的理论模型计算结果与Kumar模型计算结果之间的差异性进行了分析和探讨.研究结果表明:所推导的理论模型计算结果与实验数据更加符合,并且由于所用的推导方法不依赖于晶体的结构,因此该模型具有更好的合理性和普适性. 相似文献
2.
邢玲玲 《原子与分子物理学报》2019,36(6)
从Anderson-Grüneisen参数定义式和热膨胀系数定义式出发,根据Tallon的普遍化理论,推导出了一个用于计算弹性常数的理论模型,用所得到的理论模型分别计算了MgO和Cu两种固体材料的弹性常数 、 和 随压强以及温度变化的理论数值,并将理论计算结果与Kumar模型计算结果以及相关实验数据进行了比较,对所得到的理论模型计算结果与Kumar模型计算结果之间的差异性进行了分析和探讨。研究结果表明:所推导的理论模型计算结果与实验数据更加符合,并且由于所用的推导方法不依赖于晶体的结构,因此该模型具有更好的合理性和普适性。 相似文献
3.
邢玲玲 《原子与分子物理学报》2018,35(6)
从Anderson-Grüneisen参数定义式和热膨胀系数定义式出发,根据Tallon的普遍化理论,推导出了一个用于计算弹性常数的理论模型,用所得到的理论模型分别计算了MgO和Cu两种固体材料的弹性常数 、 和 随压强以及温度变化的理论数值,并将理论计算结果与Kumar模型计算结果以及相关实验数据进行了比较,对所得到的理论模型计算结果与Kumar模型计算结果之间的差异性进行了分析和探讨。研究结果表明:所推导的理论模型计算结果与实验数据更加符合,并且由于所用的推导方法不依赖于晶体的结构,因此该模型具有更好的合理性和普适性。 相似文献
4.
N. V. Tokiy V. V. Tokiy A. N. Pilipenko N. E. Pismenova 《Physics of the Solid State》2014,56(5):1002-1005
The possibility of applying the two-component model of single-phase hybrid materials to the explanation of the anomalous temperature dependence of elastic moduli of copper with a submicrocrystalline structure has been discussed. An analysis has been performed based on new experimental data. A twin mechanism of changes in the crystallite orientation has been proposed. These changes cause the anomalous behavior of the elastic moduli of copper during deformation and subsequent heatings. 相似文献
5.
N. P. Kobelev R. K. Nikolaev N. S. Sidorov Ya. M. Soifer 《Physics of the Solid State》2001,43(12):2344-2350
The attenuation and velocity of ultrasonic waves (at a frequency of ~4 MHz) along the 〈111〉 and 〈100〉 directions in solid C60 single-crystal samples are measured in the temperature range 100–300 K. The temperature dependences of the complete set of elastic constants for C60 fullerite are determined from the experimental data. It is shown that the specific features in the behavior of the elastic moduli near the orientational phase transition temperature are associated with different contributions of the relaxation processes to the effective elastic moduli. The activation volume and deformation potentials for the ground and excited states of the C60 low-temperature phase are evaluated from the results obtained in this work and the data available in the literature. 相似文献
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7.
High pressure and high temperature synthesized MoB2 and WB2 compacts were investigated using X-ray diffraction, energy dispersive spectroscope, scanning electron microscope, Vickers indentation test and ultrasonic measurements. Experiments showed that both MoB2 and WB2 compacts are phase pure and with a grain size of 100–200 nm. Vickers indentation test under a large loading force of 49 N showed that the Vickers hardness of MoB2 and WB2 are about 21 and 22 GPa, respectively. The bulk modulus and shear modulus are about 296 GPa, and 190 GPa for MoB2 and 349 and 200 GPa for WB2 through ultrasonic measurements. Our results indicate that MoB2 and WB2 are both hard materials with a hardness similar to that of tungsten carbide, which is widely used in industry. 相似文献
8.
A. P. Kochkin 《Journal of Experimental and Theoretical Physics》2000,90(4):628-638
Natural strain theory is used to determine the tensor of the differential elastic moduli for strains of arbitrary magnitude and its relationship is established with values measured in acoustic and mechanostatic experiments in which an additional small load is applied. For illustration purposes an expression for this tensor is given for an object which is isotropic before application of the load, and formulas to determine this tensor from the results of measurements are calculated for an anisotropic object under pressure to within the second order in terms of the shear produced as a result of its hydrostatic compression. 相似文献
9.
The pressure and temperature derivatives of the elastic moduli of single crystal LiH have been determined at room temperature, by the ultrasonic pulse echo method. From the pressure data, the mode Grüneisen parameters as well as the low and high temperature limiting values of the Grüneisen constant were computed; the latter were only slightly different. An equation of state has been constructed for LiH, and found to be in agreement with the experimental data. Based on a non-central force model, the values of the elastic moduli and their pressure derivatives have been calculated theoretically, and the latter values compared with the experimental data. 相似文献
10.
The room temperature adiabatic elastic moduli of CaO were obtained using a pulse superposition technique to measure the ultrasonic velocities. The elastic moduli were found to be (in GPa) at 298 K.
c11 | c12 | c44 |
226.2 ±0.9 | 62.4 ±0.9 | 80.6 ±0.3 The pressure derivatives of the elastic moduli, which were measured at and below room temperature, decrease with decreasing temperature. The temperature derivatives of the elastic moduli were also obtained for several temperatures below room temperature. |