Neutron Spectroscopy: Principles and Equipment

Crystallography Reports - The physical and methodical principles of inelastic thermal-neutron scattering as applied for studying condensed matter have been briefly described. The basic information...     

Neutron Reflectometry in Russia: Current State and Prospects

Crystallography Reports - The review is devoted to the current state of affairs and prospects for development in the field of neutron reflectometry on the existing and future neutron sources in the...     

Neutron Study of Internal Stress in Materials and Components

Crystallography Reports - The development and current state of instrumentation for the neutron diffraction study of internal stresses has been considered. During the last 15 years, significant...     

Compact Neutron Sources for Condensed-Matter Physics in Russia and Abroad: State of Affairs and Prospects

Crystallography Reports - A concept of a project of compact neutron source (CNS), dedicated for academical research and industrial application (DARIA), is presented. Several versions of neutron...     

Quantitative Texture Analysis: Implementation on the SKAT Neutron Diffractometer and Application in Materials and Earth Sciences

Crystallography Reports - The review focuses on some key aspects of the crystallographic texture analysis (crystallographic preferred orientations), texture measurements using time-of-flight...     

Nd:YbVO4晶体的拉曼光谱和荧光光谱研究

用群论的方法计算了Nd:YbVO4晶体的拉曼活性振动模数目,在室温下测得了其极化拉曼谱线,并指认了在不同几何配置下,各振动模式所对应的频率.同时,测得了室温下晶体的吸收谱,得到了中心波长为808 nm吸收峰的半高宽为12 nm,并在J-O理论的基础上计算了晶体的光学参数,其三个晶场参数分别为Ω2=6.88945×10-20 cm2、Ω4=4.13394×10-20 cm2、Ω6= 4.54503×10-20 cm2,并由此得到4F3/2能级的荧光寿命为178.69 μs,1062 nm处的荧光分支比为48.85;,积分发射截面为2.7867 10-18 cm2.分别在808 nm、940 nm激发下测得晶体室温发射谱,观察到了Nd→Yb以及Nd←Yb间的能量传递现象.     

Spectral Features of Zinc Phthalocyanine: Optics,Stark Spectroscopy,and Photovoltaics

Crystallography Reports - The results of spectral analysis of organic semiconductor, zinc phthalocyanine (ZnPc), which is one of the best donor materials for solar power engineering but is...     

Cs2LiYCl6∶Ce晶体的n/γ双探测闪烁性能研究

Cs₂LiYCl₆∶Ce(CLYC)晶体是一种具有n/γ双探测能力的新型闪烁晶体。采用坩埚垂直下降法生长出富⁶Li的CLYC晶体毛坯,经加工、封装得到φ50 mm×50 mm的CLYC闪烁晶体封装件,其对¹³⁷Cs 662 keV γ射线的能量分辨率为4.22%;测量²⁵²Cf中子源的脉冲波形甄别(PSD)品质因子(FOM)为3.45。凭借其优异的性能,CLYC闪烁晶体有望在中子探测领域替代³He正比计数管,并可作为n/γ双探测的优选材料,应用于中子辐射探测器、放射性同位素识别仪、个人辐射剂量仪,以及其他中子、伽马射线的探测。     

Dimethyl sulfoxide-induced dehydration of the intermembrane space of dipalmitoylphosphatidylcholine multilamellar vesicles: Neutron and synchrotron diffraction study

Small-angle neutron scattering spectra of a polydispersed population of dipalmitoylphosphatidylcholine (DPPC) unilamellar vesicles in heavy water in the presence of dimethyl sulfoxide (DMSO) are analyzed by means of the separated form-factor method. An increase in the mole fraction of DMSO in water from 0 to 15% was shown to lead to an increase in the thickness of the bilayer to the characteristics repeat distances of DPPC multilamellar membranes. This fact is indicative of dehydration of the intermembrane space and a steric contact between adjacent DPPC bilayers at 15% mole fraction of DMSO.     

Modern Methods of Neutron Radiography and Tomography in Studies of the Internal Structure of Objects

Crystallography Reports - The fundamentals, experimental possibilities, and applications of the methods of neutron radiography and tomography in studies of the structural features of large objects...     

Neutron diffraction analysis of rolling texture and its development in steels with a micro-duplex structure

In this paper first neutronographic texture investigations for two-phased steels are presented. From each of the phases three complete pole figures were measured. The analysis were carried out by means of the series expansion method. The three-dimensional orientation distribution functions of all specimens are of tubular shape. For the interpretation of the differences to single-phased steels the relationships for transformation by Kurdjumov-Sachs and by Nishiyama were utilized.     

Crystal-Chemical Features of Apatite in Carbonatites of the Tomtor Deposit (The Republic of Sakha (Yakutia), Russia): X-Ray Diffraction and Vibrational Spectroscopy Data

Crystallography Reports - An analysis of a number of samples from the Tomtor deposit of Nb and rare-earth elements (Republic of Saha (Yakutia)) by X-ray diffractometry, IR spectroscopy, and Raman...     

Erratum to:Neutron Scattering Techniques and Complementary Methods for Structural and Functional Studies of Biological Macromolecules and Large Macromolecular Complexes

Crystallography Reports - An Erratum to this paper has been published: https://doi.org/10.1134/S1063774521340034     

Photoacoustic Spectroscopy of Defect States in Etched and Air-annealed CuInSe2 Single Crystals

Photoacoustic spectra of cleaved, polished and etched, and air-annealed n-type CuInSe₂ single crystals are measured at different frequencies between 30 and 312 Hz. The spectra related to the bulk of the crystals exhibit five structures due to defects that are also present in p-type crystals. Polishing and etching as well as subsequent air annealing at 100, 200 and 300 °C reveal rather complex changes of the defect equilibrium in the near-surface region of the crystals which include both relative concentration changes of existing defects and creation of new defects. The results for polished and etched crystals correspond to trends expected from etching induced local modifications of the composition and structure as revealed by electron spectroscopies and ion channeling. Air annealing is found to affect all existing defects and to create up to five new defects which cannot be explained in terms of the related point defect model proposed by CAHEN and NOUFI.     

Nonstoichiometry in Inorganic Fluorides. IV: The Initial Stage of Anionic Nonstoichiometry in RF3 (R = Y,La, Ln)

Crystallography Reports - The anionic nonstoichiometry in inorganic fluorides is at result of substitution of F1– for O2– in the anionic sublattice. All families of fluorides exhibit...     

Co2+:BeAl2O4晶体的提拉法生长及光谱特性

应用提拉法,采用合适的化学组分配比和化料过程、以及选用适宜的固液界面温度梯度与生长速度等优化工艺条件,成功地生长出了初始Co2+离子掺杂浓度为0.15mol;、尺寸φ48×85mm2的优质Co2+:BeAl2O4晶体.测定了晶体的吸收光谱,观测到496与 640nm二个主要吸收带,它们分别归属于八面体配位中Co2+的T1(4F)→4T1(4P)跃迁与四面体配位中Co2+的A2(4F)→4T1(4P)跃迁.从晶体的吸收光谱与呈现的粉红色颜色特征可推断大多数的Co2+离子取代BeAl2O4晶体中的Al3+,形成Co2+离子的八面体格位.研究了不同光波长激发下,晶体在可见光波段的荧光特征,观测到678nm波段的荧光发射,这归属于四面体格位中Co2+的电子从4T1(4P)到4A2(4F) 能级的跃迁.     

High-Pressure Neutron Diffraction Study of the Crystal and Magnetic Structure of Materials at the Pulsed Reactor IBR-2: Current Opportunities and Prospects

Crystallography Reports - The experimental capabilities and results of recent studies of the crystal and magnetic structure of functional materials on the diffractometers DN-12 and DN-6 of upgraded...     

Quasielastic Neutron Scattering Study of Reorienting di-heptyloxyazoxybenzene (HOAB) Molecules in the Nematic and Smectic C Phases

Quasielastic neutron scattering (QNS) measurements carried out for heptyloxyazoxybenzene (HOAB) revealed the existence of fast molecular reorientation in the nematic and smectic C phases. The correlation time of this process, derived by fitting to a uniaxial rotational diffusion model, is of order of 10–20 ps in both liquid crystal phases. An explanation of the reasons for the disagreement between the correlation time values obtained by methods based on QNS and dielectric relaxation in the microwave region is suggested.