ф(x)=(1/x)integral from n=0 to x((ydy)/(e~y-1))数值表

纯金属多晶体中原子的热振动对X射线衍射强度的影响,通常由所谓Debye-Waller因子e~(-2M)来表达,其中h=普朗克常数=(6.6252±0.005)×10~(-27)尔格一秒;k=玻耳兹曼常数=(1.3804±0.0001)×10~(-16)尔格/度;m=原子质量;该金属在特定状态下的德拜示征温度。 因此中φ(x)函数对于强度计算、示征温度的计算都很有用,目前我们所能找到的φ(x)值表失之太简,x的间距太大。为了解决研究工作的需要,我们另作了计算,方法如下:     

Thermoelectric power of Ba(Fe1−x Co x )2As2 (0 ≤ x ≤ 0.05) and Ba(Fe1−x Rh x )2As2 (0 ≤ x ≤ 0.171)

Temperature-dependent, in-plane, thermoelectric power data are presented for single crystals of Ba(Fe_1?x Co _x )₂As₂ (0?≤?x?≤?0.05) and Ba(Fe_1?x Rh _x )₂As₂ (0?≤?x?≤?0.171). Given that previous thermoelectric power and angle resolved photoemission spectroscopy studies of Ba(Fe_1?x Co _x )₂As₂ delineated a rather large Co-concentration range for Lifshitz transitions to occur, and the underdoped side of the phase diagram is poorly explored, new measurements of thermoelectric power on tightly spaced concentrations of Co, 0?≤?x?≤?0.05, were carried out. The data suggest evidence of a Lifshitz transition, but instead of a discontinuous jump in thermoelectric power in the range 0?≤?x?≤?0.05, a more gradual evolution in the S(T) plots as x is increased was observed. The thermoelectric power data of Ba(Fe_1?x Rh _x )₂As₂ show very similar behavior to that of Co substituted BaFe₂As₂. The previously outlined T–x phase diagrams for both systems are further confirmed by these thermoelectric power data.     

Synthesis and native defectivity of Zn1−x V x O (0 ≤ x ≤ 0.03) photocatalysts

Nanodisperse solid solutions Zn_1?x V _x O (0 ≤ x ≤ 0.03) with high numbers of defects in an oxygen sublattice are synthesized via the precursor technique. ESR analysis reveals that V _O ⁺ oxygen vacancies are the main defects of the oxygen sublattice in the Zn_1?x V _x O structure. The Zn_1?x V _x O (0 < x ≤ 0.15) solid solutions exhibit high photocatalytic activity during hydroquinone oxidation in water upon irradiation with UV and visible light.     

LaAg x In1−x

The structures of LaAg _x In_1–x alloys withx=0.75, 0.89 are determined by neutron diffraction on powder samples. The space group isI4/mmm (D _4h ^/17 ). The lattice constants splitting, the order parameter and the mean square vibrational amplitudes of the atoms are given in the temperature range from 20 KT300 K.     

Optical spectroscopy and electronic structure of compounds HoNi5 − x Al x (x = 0, 1, 2)

The optical properties of the compounds HoNi_{5 ? x} Al _x (x = 0, 1, 2) have been investigated using the ellipsometric method in the wavelength range from 0.22 to 16 μm. The electronic structure of these intermetallic compounds has been calculated in the local electron-spin density approximation with the correction for strong electronic interactions in the 4f shell of the holmium ions. The experimental dispersion dependences of optical conductivity in the region of interband light absorption have been interpreted based on the results of the calculation of the electron density of states. The plasma and relaxation frequencies of electrons have been determined.     

Heat capacity and dielectric properties of multiferroics Bi1 − x Gd x FeO3 (x = 0–0.20)

The heat capacity and the permittivity of multiferroics Bi_{1 ? x} Gd _x FeO₃ (x = 0, 0.05, 0.10, 0.15, 0.20) have been studied in the temperature range 130–800 K. It has been found that insignificant substitution of gadolinium for bismuth markedly shifts the temperature of antiferromagnetic phase transition and increases the heat capacity over a wide temperature range. It has been shown that the temperature dependence of the excess heat capacity is due to the manifestation of three-level states. Additional anomalies characteristic of the phase transitions have been revealed in the temperature dependences of the heat capacity for the compositions with x = 0.1 and 0.15 at T ≈ 680 K and T ≈ 430 K, respectively. The results of studies of the heat capacity have been discussed simultaneously with the data of structural studies.     

Spectral luminescence properties of Ca1 ? x Sr x F2:Ce3+ (0 < x <1) crystals

The luminescence, reflection, and luminescence excitation spectra of two-component Ca_{1 ? x} Sr _x F₂:Ce³⁺ (0.05 mol %) (x = 0.14, 0.25, 0.4, 0.6, and 0.75) have been studied at room temperature and T = 8 K. It is shown that the luminescence bands (upon 130-eV photon excitation) in the range of 200 to 400 nm are attributed to singlet and triplet self-trapped exciton luminescence and to 5d-4f transitions in Ce³⁺.     

Negatron effects in CdSe1 − x Te x and ZnS1−x Se x films

Various negatron effects in films of alloys of II–VI compounds deposited from solutions as a function of the deposition mode and heat treatment are studied. It is found that the negative photocapacitance effect, which was first discovered in ZnS_1?x Se _x films, and the slowly relaxing negative photoelectric effects, which are caused by the transition of electrons located in a nanoscale surface layer from the shallow energy levels of trapping centers to deeper levels with a lower polarizability and by the presence of nanoscale clusters in these materials, which play the role of a “reservoir” for minority charge carriers, occur according to a single mechanism. A model to explain the basic laws of negative photoconductivity in CdSe_{1 ? x} Te _x films deposited from a solution is proposed. Negative residual conductivity is explained in terms of double-barrier relief model, while negative differential photoconductivity is attributed to the presence of nanoscale electric domains.     

Fine structure and magnetism of bulk Zn1 − x Cr x Se single-crystal cubic compounds (0 ≤ x ≤ 0.045)

The character of structural and magnetic features of the cubic lattice of bulk Zn_{1 ? x} Cr _x Se crystals (0 ≤ x ≤ 0.045) has been investigated using thermal neutron diffraction and magnetic measurements. It has been found that the diffraction scans of doped crystals contain effects of nuclear diffuse scattering caused by local static atomic displacements in the face-centered cubic (fcc) lattice. Results of magnetic measurements of doped crystals indicate the presence of weak antiferromagnetic correlations, which are a consequence of structural features of these compounds.     

CePt1-xRhx（0≤x≤0．9）的磁性模拟与晶场分裂

基于晶场理论,我们模拟了Kawasaki小组测量的磁化率倒数与温度关系曲线,使用点电荷晶场模型得到了伪二元合金CePt1-x,Rhx（0≤x≤0．9）的晶场分裂能和相应波函数．计算表明,Kramers离子Ce^3＋在晶场效应的作用下,基态简并部分消除得到了三个双重态,模拟得到的化合物的磁化率倒数与温度关系曲线与实验曲线...     

Structure and dielectric properties of solid solutions Bi7Ti4 + x W x Ta1–2x O21 (x = 0–0.5)

A number of solid solutions Bi₇Ti_{4 + x} W _x Ta_1–2x O₂₁ (x = 0–0.5) have been synthesized from oxides by solid-phase reaction. The crystal structure, the electrophysical characteristics, and the microstructure of the prepared ceramic samples have been studied. According to X-ray powder diffraction, all the compounds are single-phase with the structure of mixed-layer Aurivillius phases (m = 2.5) with the orthorhombic crystal lattice (space group I2cm, Z = 2). Temperature dependences of the relative permittivity ε(T) of the compound have been measured, from which it has been found that the Curie temperature T _C of perovskite-like oxides Bi₇Ti_{4 + x} W _x Ta_1–2x O₂₁ (x = 0–0.5) decreases linearly as substitution parameter x decreases. The activation energies of charge carriers have been found in different temperature ranges.     

Magnetic and Mössbauer studies on nanocrystalline Co1−x Li x Fe2O4 (x = 0, 0.2)

Ultrafine particles of Co_1???x Li _x Fe₂O₄ (x?= 0, 0.2) samples are prepared by glycine–nitrate combustion route. X-ray diffraction and transmission electron microscopy studies show that the samples have cubic spinel structure and average crystallite sizes of x?= 0 and 0.2 are 36 and 44 nm respectively. Vibrating sample magnetometer studies revealed the ferromagnetic nature of the samples. Li-doped CoFe₂O₄ sample showed higher values of coercive field, remanent magnetization and saturation magnetization compared to pure CoF₂O₄ indicating the enhancement of magnetic interactions. Mössbauer spectra at 77 K exhibited two broad sextets indicating that Fe^3?+? ions occupy both tetrahedral and octahedral sites. From these studies, it is concluded that Co_1???x Li _x Fe₂O₄ (x?= 0, 0.2) samples exhibit an inverse spinel structure. At room temperature, two sextets are superimposed on a very broad non-Lorentzian background indicating the presence of superparamgnetic fraction in agreement with the microscopic observations.     

Electron paramagnetic resonance studies on manganite Pr0.5Sr0.5Mn1−x Ga x O3 (x=0 and 0.05)

In this paper, we present the investigations of electron paramagnetic resonance on perovskite manganite Pr_0.5Sr_0.5MnO₃ and Ga-doped Pr_0.5Sr_0.5Mn_0.95Ga_0.05O₃. The temperature dependent paramagnetic resonance spectra parameters (effective g-factor, peak-to-peak linewidth ΔH _pp and double integrated intensities) have been used to study the paramagnetic spin correlations and spin dynamics. The gradual increase of effective g-factor is attributed to the presence of orbital ordering above T _C. The model fittings of temperature dependent double integrated intensities reveal Arrhenius law is appropriate for describing Pr_0.5Sr_0.5Mn_0.95Ga_0.05O₃ instead of Pr_0.5Sr_0.5MnO₃ system. As for Pr_0.5Sr_0.5MnO₃, the broadening of linewidth with the temperature increase origins from the contribution of small polaron hopping in the PM regime. However, as for Pr_0.5Sr_0.5Mn_0.95Ga_0.05O₃, the broadening of EPR linewidth can be understood with the spin-lattice relaxation mechanism.     

Structural features of the system of cubic crystals Zn0.999Fe0.001S1 ? x Se x (x = 0, 0.2)

The structural state of cubic single crystals Zn_0.999Fe_0.001S_{1 ? x} Se _x (x = 0, 0.2) obtained by the chemical transport method has been investigated using thermal neutron diffraction for the first time. It has been found that the diffraction patterns of these crystals contain the previously unknown effects of diffuse scattering caused by local statistic atomic displacements in the metastable fcc lattice.     

Ellipsometry study of interband transitions in TlGaS2xSe2(1−x) mixed crystals (0≤x≤1)

In this paper, the spectroscopic ellipsometry measurements on TlGaS_2xSe_2(1?x) mixed crystals (0≤x≤1) were carried out on the layer-plane (001) surfaces with light polarization E⊥c^? in the 1.2–6.2 eV spectral range at room temperature. The real and imaginary parts of the dielectric function, refractive index and extinction coefficient were calculated from ellipsometric data using the ambient-substrate optical model. The critical point energies in the above-band gap energy range have been obtained from the second derivative spectra of the dielectric function. Particularly for TlGaSe₂ crystals, the determined critical point energies were assigned tentatively to interband transitions using the available electronic energy band structure. The effect of the isomorphic anion substitution (sulfur for selenium) on critical point energies in TlGaS_2xSe_2(1?x) mixed crystals was established.     

玻璃中CuCl_xBr_(1-x)(x=0—1)胶体的激子光谱

一个物质未必具有大晶体一样的周期结构,但只要形成了似晶体的集团,也可以显示出晶体一样的基本光吸收。本工作研究了含CuCl_xBr_(1-x)(x=0—1)胶体的玻璃制备和光吸收性质。实验结果表明玻璃中达到一定大小的CuCl,CuCl_xBr_(1-x)和CuBr胶体粒子也可显示出与相应大块晶体相同的激子吸收光谱,玻璃具有和相应晶体相同的紫外吸收限。     

High-field magnetostriction in CeNiSn1−xGex (0≤x≤1) strongly correlated systems

Magnetization (down to 1.8 K and up to 9 T) and magnetostriction (down to 4.2 K and up to 30 T) measurements have been performed in the series of polycrystalline intermetallics CeNiSn_1?xGe_x (0≤x≤1), which show a crossover from Kondo-lattice to fluctuating valence behaviors with x increase. Magnetostriction observed can be denominated as “colossal” for a paramagnet (up to 0.68% at 150 K and 30 T), with no sign of saturation. Field, H, induced metamagnetic transitions associated to a change in Ce valence are observed. Three kinds of analysis of magnetostriction have been performed to ascertain the magnetostriction origin. At relatively low field and low temperatures these systems follow well the standard theory of magnetostriction (STM), revealing single-ion crystal field and exchange origins, and a determination of the α-symmetry microscopic magnetoelastic parameters have been performed. The valence transition is well explained in terms of the interconfigurational model, which needs an extension up to power H⁴. Application of the scaling (thermodynamics corresponding low states) allows the obtainment of the Grüneisen constant, which increases with x. Needed elastic constants measurements are also reported.     

Structure and superconductivity studies on (Y1-xLa x )Ba2Cu3O7 (0 ≤ x ≤ 1)

Studies on (Y_{1 - x}La _X )Ba₂Cu₃O₇, x = 0.0 - 1.0, in steps of 0.1, have been carried out. Results show that for x ≤ 0.4, orthorhombicity and high T_c of 90 K are retained. T_c decreases gradually for x ≥ 0.4. Pure LaBa₂Cu₃O₇ shows a T_C ^ZERO of 73 K. XRD data do not reveal any clearcut orthorhombic distortion for pure LaBa₂CuO₇ after annealing at 350°C for 4 days.     

Magnetotransmission of unpolarized infrared radiation in Hg1 − x Cd x Cr2Se4 (0 ≤ x ≤ 1) single crystals studied using the voigt geometry

The features characterizing the behavior of magnetotransmission in Hg_{1 ? x} Cd _x Cr₂Se₄ single crystals are studied using natural light in the infrared spectral range. The relation between the changes in the magneto-optical properties and in the electron band structure is found. It is shown that the most significant changes in the magnetotransmission spectrum and the band structure occur within the 0.1 < x < 0.25 range.     

Formation of Ti1–x Si x and Ti1–x Si x N films by magnetron co-sputtering

The paper reports on surface morphology, structure and microhardness of TiSi–N films formed by cosputtering from two target-facing unbalanced magnetrons, equipped with pure Ti and Si targets, on an unheated substrate rotating in front of both targets. The ratio Si/Ti in the TiSi–N film was achieved by modifying the magnitude of currents in the individual magnetrons and by the addition of nitrogen to the film. The rotation of the substrate has a strong effect on the film deposition rate and its morphology. The deposition rate is 3 times lower than that of the film deposited on a stationary substrate. The surface roughness of a polycrystalline Ti film deposited on the rotating substrate is considerably higher than that on a stationary substrate. On the contrary, the surface of an amorphous Si film is smooth and there is no difference between the roughness of Si films sputtered on stationary and on rotating substrates. The hardness of the film increases with increasing Si content and with the addition of nitrogen to the TiSi film. The Ti(26 at.%)Si(8.5 at.%)N(65 at.%)-film sputtered on an unheated rotating steel substrate, held at a floating potential, exhibited the best result with a hardness of 29 GPa.