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1.
We first demonstrate the precise Einstein-Podolsky-Rosen entanglement, which is inherent in quantum mechanics, in the context of quantum theory of complex scalar fields. We explicitly derive the entangled common eigenstates of φ1(x) - φ2(x) and П1(x) + П2(x) φ1and φ2 are two real components of the complex scalar field, and П1 and П2 are the corresponding conjugate fields) in the Fock space. The entangled eigenstates span a complete and orthonormal representation. 相似文献
2.
Temperature-dependent, in-plane, thermoelectric power data are presented for single crystals of Ba(Fe1?x Co x )2As2 (0?≤?x?≤?0.05) and Ba(Fe1?x Rh x )2As2 (0?≤?x?≤?0.171). Given that previous thermoelectric power and angle resolved photoemission spectroscopy studies of Ba(Fe1?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(Fe1?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. 相似文献
3.
Nese Kavasoglu A. Sertap Kavasoglu Sener Oktik 《Journal of Physics and Chemistry of Solids》2009,70(3-4):521-526
In this study, (ZnO)x(CdO)1?x films were prepared by ultrasonic spray pyrolysis (USP) technique at a substrate temperature of 400 °C. X-ray diffraction patterns of the films indicate that the (ZnO)x(CdO)1?x films have hexagonal wurtzite and cubic structure for the constituent materials. A decrease in the average transmission with increasing quantity of the cadmium acetate dehydrate in the sprayed solution was observed. The photoconductivity transients were performed using UV light, which has 360 nm wavelength. After light cut off, conductivity changed slowly, and the decay time was thousands of seconds. The films with x=0.2 and 0 exhibited negative photoconductivity. Temperature-dependent photoconductivity and dark conductivity measurements were performed and negative photoconductivity was also observed for the same films (x=0.2 and 0). Photoluminescence measurements were performed and band-to-band excitation energies of (ZnO)x(CdO)1?x films were determined. Band gap of the pure CdO film was found as 3.11 eV, interestingly. 相似文献
4.
D. P. Tarasov 《Technical Physics》2013,58(2):213-217
The elastic (G) and inelastic (Q ?1) properties of (Co45Fe45Zr10) x (Al2O3)100 ? x , Co x (CaF2)100 ? x , and Co x (PZT)100 ? x (x = 23–76 at %) nanocomposites obtained by ion-beam sputtering are studied in the temperature range 300–900 K. A significant rise in the Q Q ?1 (T) curve is observed at temperatures above 650 K, which is attributed to thermally activated migration of point defects under the conditions of confined geometry. 相似文献
5.
星状C60(CH3)x(PAN)x共聚物的光致发光研究 总被引:1,自引:0,他引:1
利用物理喷束淀积(PJD)技术制备C60(CH3)x(PAN)x共聚物的薄膜。这种共聚物中,C60分子位于星状结构的中心,聚丙烯腈(PAN)主链修饰在C60分子的周围。吸收及荧光光谱表明:C60分子与聚丙烯腈(PAN)有明显的相互作用,而且这种相互作用与PAN的链长有关。C60分子与PAN间存在一定的激发传递过程,从而导致PAN荧光的部分猝灭。 相似文献
6.
《Journal of Electron Spectroscopy and Related Phenomena》1987,44(1):163-174
High resolution electron energy loss Spectroscopy (HREELS), X-ray photoelectron Spectroscopy (XPS) and low energy electron diffraction (LEED) have been used to characterize initial stages of oxidation of Si(100)2x1 and Gex Si1−x (100)2x1 surfaces. Different oxidation stages of Si were identified by measuring Si 2p core level shifts and characteristic vibrations of Si-O-Si complexes. The latter may be described in the framework of continuous random network models.Then,from the experimentally determined frequencies, force constants,average bond angles and bond lengths are determined. Complementary,marker experiments with atomic hydrogen as a probe in conjunction with HREELS were used to determine the local, atomic structure for different stages of oxidation from chemical shifts of Si-H and Ge-H stretching mode intensities, respectively. 相似文献
7.
Jhumpa Adhikari 《Phase Transitions》2013,86(5):516-530
Current methods used to model the solution thermodynamics of III–V compound semiconductors involve the use of the valence force field as the molecular model and the regular solution model (with the temperature independent interaction parameter and underlying assumption of random mixing) as the engineering model. In this study, excess free energy models (with three or less adjustable parameters) are investigated to predict the solid–solid miscibility of (InAs) x (GaAs)1? x . The models investigated include the Porter/one-constant Margules (OCM) model, the two-constant Margules (TCM) model and the non-random two liquid (NRTL) model. These models are fit to excess free energy values derived from free energy change of mixing (variation with composition) data available from molecular simulations at different temperatures. The parameters in all the models have been found to be temperature dependent. The coexistence compositions are best predicted by the NRTL model, indicating the need to consider non-random mixing effects present in these solid solutions. The TCM model predicts better equilibrium composition data as compared to the OCM model. 相似文献
8.
The specific heat in (KBr)1–x(KCN)x has been measured for concentrations 0.00x0.93 and for temperatures 2 KT50 K. In addition, the dipolar relaxation phenomena were studied using dielectric spectroscopy. The relaxation behaviour was parametrized assuming a Gaussian distribution of energy barriers and the mean activation energies, the distribution widths, and the attempt frequencies have been determined as a function of the CN– concentration. With these parameters the linear and the excess specific heat contributions were calculated and compared to the calorimetric results. 相似文献
9.
X-ray diffraction has been used for studying the fine crystal structure of metastable cubic oxide compounds Ni(1 ? x)Zn x O (0.60 ≤ x ≤ 0.99) obtained from the initial hexagonal phase by quenching of the samples at a high temperature and under external hydrostatic pressure. It has been found that the diffraction patterns of these compounds include a system of diffuse superstructure maxima, whose number and intensity essentially depend on the composition. The origin of this superstructure has been discussed. 相似文献
10.
(Ni, Cu)-rich Ti–Ni–Cu amorphous films with a Cu content of 6.2–33.5 at. % formed by sputtering were annealed at 773, 873 and 973 K for 1 h and their microstructures investigated. Two types of precipitate were observed in the annealed films: a Ti(NiCu)2 phase for the Ti48.5Ni40Cu11.5, Ti48.6Ni35.9Cu15.5, Ti48.3Ni28.4Cu23.3 and Ti48.3Ni23.9Cu27.8 films, plus a TiCu phase for the Ti48.5Ni18Cu33.5 films. These precipitates were found to have coherency with the B2 matrix in the films annealed at 773 K and were densely distributed within the grains. However, in the films annealed at 873 K, their size increased 10-fold and their density decreased. Annealing at 973 K promoted grain-boundary precipitation and, accordingly, the density of the precipitates in the grain interiors decreased. On the other hand, the annealed Ti48.9Ni44.9Cu6.2 films showed no precipitates in their grain interiors, but the number of grain-boundary precipitates increased with increasing annealing temperature. It was also found that grain size decreased with increasing Cu content and was significantly decreased for the Ti48.5Ni18Cu33.5 films. 相似文献
11.
A model has been proposed to calculate the and dependences in the Y 1?b(Ca)bBa2Cu3O6+x high- cuprate family and applied to , , and cases, for which experimental data exist in the literature. The results obtained imply that the Ca efficiency to provide holes is independent of the basal plane oxygen concentration, which is consistent with a view that electrons from CuO2 layers would go primarily to Ca since it is twice closer than oxygen (in addition, the chain oxygen is screened by a layer made up of Ba and O(4) ions). It is shown that, in fully oxygenized compounds () the average efficiency, , of a chain oxygen to attract an electron from the two nearby layers is reduced by the Ca insertion, though not because the charge transfer mechanism is in itself weakened by Ca, but because a part of electrons that are otherwise available in CuO layers has already been removed by the substitution of Y 3+ with Ca2+. It has been found that the -dependence of the average oxygen doping efficiency can be fairly accurately described by the following relation: . The calculated and dependences are in very good agreement with the available experimental data. 相似文献
12.
V. V. Rylkov S. N. Nikolaev K. Yu. Chernoglazov B. A. Aronzon K. I. Maslakov V. V. Tugushev E. T. Kulatov I. A. Likhachev E. M. Pashaev A. S. Semisalova N. S. Perov A. B. Granovskii E. A. Gan’shina O. A. Novodvorskii O. D. Khramova E. V. Khaidukov V. Ya. Panchenko 《JETP Letters》2012,96(4):255-262
It has been found that the Curie temperature (T C ?? 300 K) in nonstoichiometric Si1 ? x Mn x alloys slightly enriched in Mn (x ?? 0.52?C0.55) in comparison to the stoichiometric manganese monosilicide MnSi becomes about an order of magnitude higher than that in MnSi (T C ?? 30 K). Deviations from stoichiometry lead to a drastic decrease in the density of charge carries (holes), whereas their mobility at about 100 K becomes an order of magnitude higher than the value characteristic of MnSi. The high-temperature ferromagnetism is ascribed to the formation of defects with the localized magnetic moments and by their indirect exchange interaction mediated by the paramagnetic fluctuations of the hole spin density. The existence of defects with the localized magnetic moments in Si1 ? x Mn x alloys with x ?? 0.52?C0.55 is supported by the results of numerical calculations performed within the framework of the local-density-functional approximation. The increase in the hole mobility in the nonstoichiometric material is attributed to the decay of the Kondo (or spin-polaron) resonances presumably existing in MnSi. 相似文献
13.
14.
文中报道了 Bi_(1.9)Sb_(0.1)Sr_2Ca_2Cu_(2+x)O_y,系列的交流磁化率测量及 X 射线衍射结果,发现超导转变温度对于 Cu 的组份非常敏感,当 x=0.4时,样品在136.5K 出现抗磁性,其 X 射线衍射图中新相衍射峰较85K 超导相的峰更强,因此 Cu 的价态和配位数在形成高和 T_c 超导相中起着至关重要的作用. 相似文献
15.
The shape memory behaviour of (Ni,Cu)-rich Ti–Ni–Cu thin films (Ti48.9Ni44.9Cu6.2, Ti48.5Ni40Cu11.5, Ti48.6Ni35.9Cu15.5, Ti48.3Ni28.4Cu23.3, Ti48.3Ni23.9Cu27.8 and Ti48.5Ni18Cu33.5) annealed at 773, 873 and 973 K for 1 h was investigated. The films with 6.2, 11.5–15.5 and 23.3–33.5 at% Cu showed a single-stage deformation due to a B2 ? B19′ transformation, a two-stage deformation due to the B2 ? B19 ? B19′ transformation and a single-stage deformation due to the B2 ? B19′ transformation, respectively. The martensitic transformation start temperature (M s) increased with increasing Cu content and then levelled off for more than 15 at% Cu, indicating a high Ms temperature of 345 K. Temperature hystereses were almost 15 K for all films with more than 10 at% Cu. The critical stress for slip increased with increasing Cu content and increased significantly for the Ti48.5Ni18Cu33.5 film, whereas the maximum recoverable strain significantly decreased for the Ti48.5Ni18Cu33.5 film. With decreasing annealing temperature, the critical stress for slip increased, but the M s temperature decreased. It was found that films with 11.5 at% Cu or more, annealed at 873 K, showed a high martensitic transformation temperature and a high critical stress for slip. 相似文献
16.
The phase diagram of (NaCN)1–x(KCN)x was examined by neutron powder diffraction in the temperature range 5K T300 K. Several non-cubic low-temperature phases were identified for concentrationsx<x
c1=0.15 andxx
c2=0.89. Lattice parameters and ferroelastic deformations were determined from the observed powder patterns. The phase transformations were characterized following the temperature dependence of the appropriate order parameters. 相似文献
17.
18.
《光学学报》2010,(7)
通过调节基质组份比例,研究了SrAl2xO3x+1∶Eu2+,Dy3+(x=1~2)荧光粉晶体结构,发光性质及长余辉特性。选取硝酸锶和硝酸铝作为基质原材料,硼酸氨和氟化铝作为助溶剂,采用阳离子草酸盐共沉淀,湿法预先混合原材料及分步合成等方法,制备了亮度高、余辉长及良好粒径分布的系列长余辉发光材料。基于对样品X射线衍射(XRD)图谱,扫描电子显微镜(SEM)照片,激发、发射光谱及余辉衰减曲线分析,发现SrAl2xO3x+1∶Eu2+,Dy3+具有良好的结晶状态;随x增加,发射光谱峰值从520 nm蓝移至470 nm;衰减到可辨认发光强度0.32 mcd/m2,余辉时间可相应地从30 h延长到60 h以上。通过分析发现表现不同余辉特性的主要原因是Eu2+在基质中具有不同浓度、不同衰减寿命的蓝、绿两种发光中心造成的,其中蓝发光中心寿命明显高于绿发光中心。 相似文献
19.
《Current Applied Physics》2002,2(2):167-174
In electrical properties, the dc conductivity and photoconductivity measurements have been made in vacuum evaporated thin films of a-(Se70Te30)100−x(Se98Bi2)x system, in the temperature range (308–355 K). It has been observed that dc conductivity and activation energy depend on the Bi concentration. Photocurrent dependence on incident radiation has also been observed which follow the power law (Iph∝Fγ). Transient photocurrent exhibits the non-exponential decay time. All these parameters show that the recombination within the localized states is predominant. In crystallization kinetics, the heating rate dependence of glass transition and crystallization temperatures is studied to calculate the activation energy for thermal relaxation and activation energy for crystallization. The composition dependence of the activation energy for thermal relaxation and activation energy for crystallization is discussed in terms of the structure of Se–Te–Bi glassy system. 相似文献
20.
为了确定ZrO2和(ZrO2)0.97(Bi2O3)0.03的晶体结构和原子热振动各向同性温度因子B,对该粉末晶体进行X射线衍射实验,建立了晶体结构模型,进行晶体结构分析。首先,采用共沉淀法和高温固相烧结法制备了纳米氧化锆ZrO2和(ZrO2)0.97(Bi2O3)0.03粉末晶体,接着,使用X射线测试仪对两种样品进行了衍射实验(XRD),利用Rietveld 精修方法的 RIETAN-2000程序对所得实验结果进行了晶体结构分析,获得了晶体结构参量和原子热振动各向同性温度因子B。通过Maximum Entropy Method(MEM)解析得到了粉末晶体(ZrO2)x(Bi2O3)1-x(x=1.0,0.97)的等高电子密度分布可视化图谱。结果表明,(ZrO2)0.97(Bi2O3)0.03的晶胞体积比ZrO2的晶胞体积大分别为140.6850 Å3和140.5637Å3;ZrO2晶体的原子热振动各向同性温度因子B(Zr)、BO(1)、BO(2)和 B(Bi)分别为0.690、0.269、 0.178 和 0 Å2,(ZrO2)0.97(Bi2O3)0.03晶体的分别为0.460 、0.583 、0.121 和0.581 Å2。 确定了(ZrO2)0.97(Bi2O3)0.03的晶体结构属于单斜晶系,实现了等高电子密度分布三维(3D)和二维(2D)的可视化,进一步确定了晶体结构和原子位置。 相似文献