Specific Heat Capacity and the Debye Temperature of a Compressed Crystalline Neon in the Model of Deformable Atoms

Physics of the Solid State - The thermodynamic properties of a compressed Ne crystal are studied theoretically ab initio with the allowance for the many-body interaction in the deformable atom...     

Relation between Liquation and the Debye Temperature

Technical Physics - It has been established that several parameters characterizing liquation are associated with the Debye temperature of chemical elements. The correlation factors always exceed 0.9.     

金属比热容与温度关系的实验研究

比热容是金属的一个重要参数,金属的比热容与金属的温度有关。以铜为标准样品,利用金属比热容测量仪测量了铁和铝在50~200℃范围内的热容量。利用Mathematica软件拟合出铁和铝的热容量与温度的关系曲线,得到了金属比热容与温度之间的关系。     

利用DISLab温度传感器测金属比热容

针对用冷却法测金属比热容实验的不足,对实验进行了改进。利用DISLab温度传感器测量金属样品在冷却过程中,温度随时间的变化速率,以解决传统的冷却法测金属比热容实验中,用热电偶和秒表测量时产生的误差较大问题。实验表明,该实验方法与传统实验相比,不仅操作简便,而且精度高,具有明显的优势。     

碱金属卤化物键长、德拜温度和热膨胀系数的温度效应

以碱金属卤化物为研究对象,根据局域键平均近似方法,从热膨胀系数的定义出发,建立热膨胀系数和键长的温度效应函数表达式。定量获取碱金属卤化物的键长、刚性因子、德拜温度和热膨胀系数。结果表明：①碱金属卤化物的热膨胀系数与结合能成反比;②同类碱金属卤化物中,从氟碱化物到碘碱化物德拜温度逐渐减小而热膨胀系数逐渐增大;③碱金属卤化物的键长在其德拜温度的三分之一处,由非线性转变为线性热伸长。     

Temperature-Dependent Transport Properties in Oxide p-n Junction above Room Temperature

Oxide p-n junctions ofp-SrIn_0.1Ti_0.9O₃/n-SrNb_0.01Ti_0.99O₃ (SITO/SNTO) are fabricated by laser molecular beam epitaxy. The current-voltage characteristics of the SITO/SNTO p-n junction are investigated mainly in the temperature range of 300--400K. The SITO/SNTO junction exhibited good rectifying behaviour over the wholetemperature range. Our results indicate a possibility of application of oxide p-n junction in higher temperatures in future electronic devices.     

Specific Heat and Magnetic Susceptibility of Graphene: A RenormalizationGroup Study

In the present paper, we study effect of the long-range Coulomb interaction on the thermodynamic properties of graphene by renormalization group methods. Our calculations show that both the specific heat and the magnetic susceptibility of the material behave differently from the Landau Fermi liquid. More precisely, we find that these quantities are logarithmically suppressed with respect to its noninteracting counterpart when temperature is low.     

用X射线衍射强度测定纳米金刚石的德拜特征温度和熔点

 采用陆学善、梁敬魁提出的方法，利用纳米金刚石的X射线衍射强度，计算出它的德拜特征温度为411.7 K，比高温高压合成出的大颗粒金刚石单晶的德拜特征温度（2 200 K）低了许多；且其原子晶格振动的振幅比高温高压合成得到的大颗粒金刚石单晶原子的振幅增大了4.37倍；用Lindemann公式计算出纳米金刚石的熔点为2 070 K，约为高温高压合成出的大颗粒金刚石单晶熔点（4 400 K）的一半。这将导致纳米金刚石原子间结合力的减弱，势必造成其活性的增大，从而引起物理、化学性能的改变。     

Temperature dependence of the elastic constants and Debye temperatures of NaCl and KCl single crystals

A pulsed ultrasonic method has been used to measure the temperature dependences of the elastic moduli, the constants C_ik and S_ik , the anisotropy factors, the bulk moduli, and the Poisson ratios over the temperature range 300-120 ° K for NaCl and over the range 300-80 ° K for KCl. The Debye temperatures of these compounds are calculated from the elastic constants extrapolated to 0 ° K.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii Fizika, No. 6, pp. 22–28, June, 1970.     

比热容教学探讨--物理学史与科学探究之三

对“比热容”的课堂探究教学和历史上的真实探究过程进行了比较，认为目前的课堂探究教学有利于培养学生的实验技巧和动手能力，而与此相关的物理学史资料能使学生了解科学概念的发展及其重要作用，从而学习科学家的研究方法，领悟科学思想和精神．因此，物理学史料的补充能够使课堂的科学探究活动收到更好的教学效果．     

Temperature dependence of the Debye screening length in heavily doped semiconductors having Gaussian band-tails

In the present work, a generalized expression is derived for the Debye screening length of the carriers in heavily doped semiconductors having Gaussian band-tails. The temperature dependence of the screening length is also computed for such semiconductors, taking n-type GaAs as an example.On leave of absence fromthe Department of Physics, B. N. College, University of Patna, India.     

Features of the Temperature Dependence of Graphene Oxide Resistivity

The Raman spectra and the temperature dependence of the resistivity of graphene oxide grown upon continuous heating and cooling on a glass substrate is studied in air in the temperature interval of 300–550 K. It is established that the intensity of the D-peak falls relative to the G-peak, the maximum of which shifts toward lower frequencies in Raman spectra. Partial removal of oxygen-containing functional groups is accompanied by a reduction in resistivity from 5.6 × 10⁹ to 5.4 × 10⁹ Ω. In the temperature intervals of 300–350 K and 300–375 K, the resistivity is constant upon graphene oxide heating and cooling, respectively.     

Debye screening of dislocations

Debye-like screening by edge dislocations of some externally given stress is studied by means of a variational approach to coarse grained field theory. Explicitly given are the force field and the induced geometrically necessary dislocation (GND) distribution, in the special case of a single glide axis in 2D, for (i) a single edge dislocation and (ii) a dislocation wall. Numerical simulation demonstrates that the correlation in relaxed dislocation configurations is in good agreement with the induced GND in case (i). Furthermore, the result (ii) well predicts the experimentally observed decay length for the GND developing close to grain boundaries.     

Bremsstrahlung of Debye plasma

The effect of Debye screening on the bremsstrahlung spectrum and total bremsstrahlung intensity of plasma is calculated. As compared with the Coulomb field approximation (infinitely large Debye radiusL) an additional density and temperature dependence of the radiation intensity is found. Results are expressed in terms of a dimensionless parameter=²/2mL ² kT, wherem is the rest mass of an electron and other symbols have their standard meaning. Deviations from the Coulomb field approximation become significant for the values 10^–3.I am grateful to Dr. J.Horáek and Dr. J.Obdrálek for their help in performing the numerical calculations.     

高温还原氧化石墨烯膜及其导热性能

采用氧化还原法制备了结构致密且具有较高柔韧性的石墨烯薄膜,探究了薄膜经过较高退火温度还原后结构变化,并通过T型稳态法测量了其热导率,研究了还原温度对薄膜热导率和力学性能的影响。结果表明,高温还原有助于氧化石墨烯中含氧官能团的去除和sp2杂化碳晶格的恢复,并且温度越高还原效果越好。当还原温度高达2800℃时,在200~350 K温度范围内石墨烯膜的热导率在336.9~436 W·m^-1·K^-1之间,伴随着温度的升高,热导率有先增大后减小的趋势。     

Coulomb Screening and Plasmon Excitation in Graphene at Finite Temperature

By using the random phase approximation (RPA) in many-body perturbation theory, we calculate the polarization function of the electron gas in graphene at finite temperature. Based on this, we calculate the temperature dependent dielectric function ε(q). The thermal effect on ε(q) in various q regions is discussed. The temperature dependence is found to be quadratic. We also investigate the plasmon dispersion relation at finite temperature, with the zero-temperature relation as a special case. The result is in good agreement with recent experimental data.     

Debye temperature of cubic crystals

An algorithm for determination of the Debye temperature is presented, which enables the easy computation of the Debye temperature for arbitrary stable cubic crystal.     

X-ray Debye temperature of silver

The theory of Paskin regarding the temperature variation of the X-ray Debye temperature has been modified by including the additional self-energy anharmonic effect which depends on phonon-phonon interaction. It is shown that the isobaric Grüneisen parameter combines the crystal anharmonicity due to the volume expansion and the self-energy effect. Using the data on the isobaric Grüneisen parameter the calculated results on the temperature variation of the X-ray Debye temperature of silver show satisfactory agreement with the experimental data.