Combined Use Of X-ray Diffraction Research Articles

Characterization and mechanism study of sulfate saline soil solidification in seasonal frozen regions using ternary solid waste-cement synergy

Infrastructures built on sulfate saline soil foundations in seasonal frozen regions are highly susceptible to salt-frost heave damage and salt corrosion. To address this issue, a method has been proposed utilizing a ternary blend of industrial solid waste materials - fly ash (FA), silica fume (SF), and brick powder (BP) - in conjunction with Portland cement (PC) for the solidification of sulfate saline soil. The feasibility of this solidification technique has been validated through a series of tests, including unconfined compressive strength tests, freeze-thaw cycle tests, salt leaching tests, and microstructural analysis. The results showed that: The unconfined compressive strength of the solidified saline soil at 56 days increased by up to 61.27 times compared to untreated saline soil. During the freeze-thaw cycles, the volume of salt-frost heave in the solidified saline soil was only 10.75% of that in untreated soil, with a reduction in salt-frost heave force by up to 90.94%. Furthermore, during the salt leaching process, the rate of salt migration in the solidified saline soil could be slowed by up to 4.15 times, while the total amount of salt leached was only 31.34% of that in untreated saline soil. Additionally, through the combined use of X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray Spectroscopy (EDS), it was discovered that the interactive synergistic effect of the solidifying agents in a SO42- rich environment facilitated the dissolution of Si-O and Al-O micro-lattices on the surface of the solidifying agent particles. This led to the extensive formation of C-(A)-S-H gels and AFt products, resulting in the transformation of the soil structure from dispersed to flocculated. The comprehensive test results indicate that the mechanical properties, frost resistance, and salt corrosion resistance of the solidified saline soil have significantly improved, with an optimal solidifying agent mixture ratio of 3% PC, 5% FA, 5% SF, and 6% BP. These findings can provide a reference for the solidification treatment of sulfate saline soil foundations in seasonal frozen regions.

Determination of the figurative point trajectory on the phase diagram of NiO lithiation-oxidation process by x-ray diffraction and Compton scattering methods.

The positions of the figurative points on the triangular Gibbs phase diagram for the process of high-temperature synthesis of solid solutions LiyNi2-yO2 were determined for the first time using a combination of x-ray diffraction (XRD) and Compton scattering methods. The trajectory of the figurative point is built according to experimental data for temperatures of 650 and 750 °C. The ratios of the phases in equilibrium are found. It was established that, when the structure goes from rock salt to layered structures, the composition of the reagent mixture changes nonmonotonically: with an increase in the degree of ordering of the solid solution lattice, the sum molecular weight of the solid reagents increases. It has been shown experimentally that the combined use of XRD and Compton scattering makes it possible to carry out physicochemical analysis of the process and predict the final product.

Betamethasone Dipropionate Derivatization, Biotransformation, Molecular Docking, and ADME Analysis as Glucocorticoid Receptor.

Betamethasone is an important glucocorticoids (GCs), frequently used to cure allergies (such as asthma and angioedema), Crohn's disease, skin diseases (such as dermatitis and psoriasis), systemic lupus erythematosus, rheumatic disorders, and leukemia. Present investigation deals to find potential agonist of glucocorticoid receptors after biotransformation of betamethasone dipropionate (1) and to carry out the molecular docking and ADME analyses. Biotransformation of 1 was carried out with Launaea capitata (dandy) roots and Musa acuminate (banana) leaves. M. acuminate furnished low-cost value-added products such as Sananone dipropionate (2) in 5% yields. Further, biocatalysis of Sananone dipropionate (2) with M. acuminate gave Sananone propionate (3) and Sananone (4) in 12% and 7% yields, respectively. However, Sananone (4) was obtained in 37% yields from Launaea capitata. Compound 5 was obtained in 11% yield after β-elimination of propionic acid at C-17 during oxidation of compound 1. The structure elucidation of new compounds 2-5 was accomplished through combined use of X-ray diffraction and NMR (1D and 2D) studies. In addition to this, molecular docking and ADME analyses of all transformed products of 1 were also done. Compounds 1-5 showed -12.53 to -10.11 kcal/mol potential binding affinity with glucocorticoid receptor (GR) and good ADME profile. Moreover, all the compounds showed good oral bioavailability with the octanol/water partition coefficient in the range of 2.23 to 3.65, which indicated that compounds 1-5 were in significant agreement with the given criteria to be considered as drug-like.

Microstructural characteristics and hardness of CoNiTi medium-entropy alloy coating on pure Ti substrate prepared by pulsed laser cladding

A ternary CoNiTi medium-entropy (MEA) alloy coating was successfully fabricated on pure Ti substrate by utilizing pulsed laser cladding. Phase constitutions and microstructural characteristics of the coating were analyzed by combined use of X-ray diffraction, electron channeling contrast imaging, secondary electron imaging, energy dispersive spectroscopy and electron backscatter diffraction techniques. Results show that three zones with distinct microstructures are formed after the pulsed laser cladding treatment: cladding zone (CZ), bonding zone (BZ) and heat-affected zone (HAZ). Dendritic (BCC solid-solution phase)-interdendritic (Ti2Ni type phase) structures are formed in the CZ with many nanoparticles (Ti2Co type phase) dispersed inside the interdendritic structures. The BZ consists of fine acicular grains while the HAZ below the BZ is composed of irregular-shaped bulk grains. Hardness measurements reveal that hardness of the MEA coating reaches 571 ± 46 H V, which is ∼5 times that of the substrate (114 ± 4 H V). Comprehensive analyses show that such high hardness can be attributed to the combined contributions from solid-solution hardening of the BCC phase and second-phase hardening from the Ti2Ni and Ti2Co type intermetallic compounds.

Typical Microstructural Characteristics of Ti–5Al–5Mo–5V–3Cr–1Fe Metastable β Ti Alloy Forged in α + β Region

In this study, typical microstructural characteristics of a metastable β Ti alloy (Ti–5Al–5Mo–5V–3Cr–1Fe) forged in a dual-phase region (strain of 54% at 820 °C) were investigated in detail by the combined use of X-ray diffraction, energy dispersive spectroscopy, electron channeling contrast imaging and electron backscatter diffraction techniques. Results show that the microstructure of the forged alloy is composed of bulk α grains, α plates and β matrix. The bulk α grains correspond to retained primary α phase (αp, average grain size ~ 2.4 μm), while the α plates are secondary α phase (αs, width ~ 70 nm) precipitated from the β matrix during air cooling. During forging, the β matrix experiences dynamic recovery with many subgrains and significant orientation gradients formed. Analyses of the orientation relationship between the α and β phases show that the Burgers orientation relationship is not maintained between some αp and β phases, which should be related to thermal deformation-induced changes of their orientations. In contrast, all of the αs plates are found to maintain well the Burgers orientation relationship with the β phase.

Microstructural characteristics and properties of CoCrFeNiNbx high-entropy alloy coatings on pure titanium substrate by pulsed laser cladding

CoCrFeNiNbx (x = 0 or 1 at.%) high-entropy alloy (HEA) coatings with good metallurgical bonding were successfully prepared on surfaces of pure titanium sheets by pulsed laser cladding. Phase constitutions and microstructural characteristics of the HEA coatings were characterized and analyzed by combined use of X-ray diffraction, electron channeling contrast imaging, energy dispersive spectroscopy and electron backscatter diffraction techniques. Results show that the HEA coating without Nb is consisted of BCC solid-solution phase with equiaxed bulk grain morphology and Cr2Ti Laves phase (C14-type hexagonal structure) with fine interdendritic lamellar morphology. After adding 1 at.% Nb, in addition to the BCC solid-solution phase and the Cr2Ti Laves phase, Cr2Nb Laves phase with C15-type cubic structure also appears in the interdendritic region in the HEA coating. Hardness tests reveal that the CoCrFeNiNbx HEA coatings are significantly harder than the pure titanium substrate (~122 HV). The hardness value of the HEA coating with 1 at.% Nb reaches 1008 HV, which is ~ 8.3 times that of the substrate and considerably higher than that of bulk HEAs with similar compositions. Such high hardness can be attributed to the combined contribution from solid-solution hardening, and hardening from grain refinement and Laves phases with fine lamellar morphologies.

Remote epitaxy using graphene enables growth of stress-free GaN

The properties of group III-Nitrides (III-N) such as a large direct bandgap, high melting point, and high breakdown voltage make them very attractive for optoelectronic applications. However, conventional epitaxy on SiC and sapphire substrates results in strained and defective films with consequently poor device performance. In this work, by studying the nucleation of GaN on graphene/SiC by MOVPE, we unambiguously demonstrate the possibility of remote van der Waals epitaxy. By choosing the appropriate growth conditions, GaN crystals can grow either in-plane misoriented or fully epitaxial to the substrate. The adhesion forces across the GaN and graphene interface are very weak and the micron-scale nuclei can be easily moved around. The combined use of x-ray diffraction and transmission electron microscopy demonstrate the growth of stress-free and dislocation-free crystals. The high quality of the crystals was further confirmed by photoluminescence measurements. First principles calculations additionally highlighted the importance of the polarity of the underlying substrate. This work lays the first brick towards the synthesis of high quality III-N thin films grown via van der Waals epitaxy.

Vibrational Properties of Pd Nanocubes.

The atomic disorder and the vibrational properties of Pd nanocubes have been studied through a combined use of X-ray diffraction and molecular dynamics simulations. The latter show that the trend of the mean square relative displacement as a function of the radius of the coordination shells is characteristic of the nanoparticle shape and can be described by a combined model: A correlated Debye model for the thermal displacement and a parametric expression for the static disorder. This combined model, supplemented by results of line profile analysis of the diffraction patterns collected at different temperatures (100, 200, and 300 K) can explain the observed increase in the Debye–Waller coefficient, and shed light on the effect of the finite domain size and of the atomic disorder on the vibrational properties of metal nanocrystals.

Non-Invasive and Non-Destructive Examination of Artistic Pigments, Paints, and Paintings by Means of X-Ray Methods.

Recent studies are concisely reviewed, in which X-ray beams of (sub)micrometre to millimetre dimensions have been used for non-destructive analysis and characterization of pigments, minute paint samples, and/or entire paintings from the seventeenth to the early twentieth century painters. The overview presented encompasses the use of laboratory and synchrotron radiation-based instrumentation and deals with the use of several variants of X-ray fluorescence (XRF) as a method of elemental analysis and imaging, as well as with the combined use of X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS). Microscopic XRF is a variant of the method that is well suited to visualize the elemental distribution of key elements, mostly metals, present in paint multi-layers, on the length scale from 1 to 100μm inside micro-samples taken from paintings. In the context of the characterization of artists' pigments subjected to natural degradation, the use of methods limited to elemental analysis or imaging usually is not sufficient to elucidate the chemical transformations that have taken place. However, at synchrotron facilities, combinations of μ-XRF with related methods such as μ-XAS and μ-XRD have proven themselves to be very suitable for such studies. Their use is often combined with microscopic Fourier transform infra-red spectroscopy and/or Raman microscopy since these methods deliver complementary information of high molecular specificity at more or less the same length scale as the X-ray microprobe techniques. Since microscopic investigation of a relatively limited number of minute paint samples, taken from a given work of art, may not yield representative information about the entire artefact, several methods for macroscopic, non-invasive imaging have recently been developed. Those based on XRF scanning and full-field hyperspectral imaging appear very promising; some recent published results are discussed.

Oxidation controlled phase composition of FeCo(Zr) nanoparticles in CaF2 matrix

Results of the study of oxidised (FeCoZr)х(CaF2)100−х films in a wide composition range (30≤х≤74at.%) sintered at oxygen pressures PO=4.3 and 9.8mPa with X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray absorption spectroscopy (XAS), 57Fe Mössbauer spectroscopy (MS), and vibrating sample magnetometry (VSM) are reported.A “crystalline metallic core–amorphous oxide shell” structure of nanoparticles (NPs) in films oxidised at lower PO=4.3mPa is observed in TEM images. A combined use of XRD, MS and XAS techniques provides identification of NP phase composition evidencing α-FeCo(Zr) core of the variable content depending on x and a complex oxide shell including amorphous α-Fe3+2O3 together with Co2+1−yFe2+yO at low x (30–36at.%). Full oxidation of NPs at higher PO=9.8mPa is indicated by TEM, XRD, MS and XAS patterns evidencing the formation of “crystalline Co2+1−yFe2+yO core–amorphous α-Fe3+2O3 shell” structure. Progressive oxidation of NPs with decreasing x at PO=4.3mPa as well as with PO increase is followed by variation of average centre shifts <δ> obtained from deconvoluted 57Fe Mössbauer spectra. Magnetometry measurements of films sintered at PO=4.3mPa reveal an effect of exchange bias confirming “ferromagnetic metallic core–antiferromagnetic oxide shell” structure of NPs.The results show that phase composition of oxide shells is governed both by concentration of oxygen available during synthesis and on the x. Schemes of progressive NP oxidation with identified phase composition as a function of PO and x values are proposed.

Alteration of fossil-bearing shale (Autun Basin, France; Permian), part I: Characterizing iron speciation and its vulnerability to weathering by combined use of Mössbauer spectroscopy, X-ray diffraction, porosimetry and permeability measurements

Fossil-bearing shale specimens that include sulfides in their compositions are chemically reactive and sometimes also mechanically fragile. This decay is often related to iron sulfate efflorescence resulting from the oxidation of sulfide compounds. The processes underlying these degradations are poorly known, thus impeding the elaboration of curative or preventive treatments. The present contribution aims to identify the origin of museum specimen alterations. It focuses on the Flouest collection housed at the Muséum national d’Histoire naturelle (MNHN, Paris, France) and originating from the Autun Basin (Saône-et-Loire, France; Permian). To evaluate the alteration of MNHN specimens, it appeared necessary to compare their composition with that of unaltered shale so as to identify chemical changes occurring during ageing. Therefore new material was collected in the Autun Basin, among others on the locality of Muse that corresponds to the same lithostratigraphic unit than that of the MNHN specimens. The present article focuses on the combined use of X-ray diffraction and Mössbauer spectrometry for characterizing the speciation and reactivity of iron within the shale matrix. Crystalline pyrite was evidenced by X-ray diffraction (XRD) on one sample only and elemental analysis showed that iron is present in large excess with respect to sulfur. Iron sulfide, if present, involves a minor fraction of iron. A more complete characterization of iron-bearing phases was achieved with Mössbauer measurements, showing that a great part of iron, between approx. 25% and 65%, corresponds to iron(II) incorporated in clay minerals (illite and vermiculite were detected by XRD). Similar percentages of these iron(II) signatures were found for MNHN specimens and new shale samples, suggesting that iron(II) present in clays is not affected by ageing. This point is complementary highlighted by porosity and permeability measurements showing that the pore size distribution of the samples originating from Muse is mostly unimodal and narrow (average radius below 10nm). As a result, the shale is poorly permeable to water and almost fully impermeable to oxygen. This might explain the poor reactivity of iron(II) during ageing. Iron(III)-bearing phases were also identified. On new shale samples, they exclusively involve clay minerals. On MNHN specimens, poorly crystallized iron(III) sulfates are additionally observed. The presence of iron(III) oxyhydroxides appeared unlikely. The change of iron speciation provoked by the alteration of the matrix also mainly corresponds to the emergence of more or less crystallized iron(III) sulfates probably formed though iron sulfide oxidation. These phases however remain in the inner part of shale and cannot account for the large efflorescence of iron(II) sulfates observed nearby the fossil.

Reversibly in-situ anchoring copper nanocatalyst in perovskite titanate cathode for direct high-temperature steam electrolysis

This paper investigates a potential cathode material (La0.2Sr0.8)0.9Ti0.9Cu0.1O3−δ (LSTCO) with A-site deficiency and B-site excess which was designed as a parent material for anchoring exsolved copper nanocatalyst on the surface of La0.2Sr0.8TiO3+δ (LSTO) through a high-temperature reduction. Physical characterization of the samples by combined use of X-ray diffraction, scanning electron microscope, energy-dispersive spectroscopy, thermogravimetric analyzer and X-ray photoelectron spectroscopy indicated that the exsolution and dissolution of the Cu nanoparticles in the cathode was completely reversible in the redox cycles. Electrical properties of LSTO and LSTCO were systematically investigated which correlated closely with electrochemical performance of the composite electrodes in symmetrical cells and electrolysis cells. Polarization resistance (Rp) of the symmetrical cells was improved from 3 Ω cm2 of the LSTO to 1.5 Ω cm2 of the LSTCO in hydrogen atmosphere at 800 °C. Current efficiencies of the solid oxide electrolyzer with Cu-anchored LSTO cathode were found to be enhanced by approximately 20% compared to the bare cathode with or without reducing gas flowing over them under the applied voltage of 2.0 V at 800 °C, respectively.

Ancient silver extraction in the Montevecchio mine basin (Sardinia, Italy): micro-chemical study of pyrometallurgical materials

Different pyrometallurgical materials such as slags, refractory materials and thermally treated lead ores likely related to smelting and extractive processes and chronologically related to Punic and Roman periods (IV–III BC) have been found at Bocche di Sciria and Conca e Mosu in the Montevecchio mine basin (south western Sardinia, Italy), where archaeological findings and classical authors locate extractive metallurgy activities since pre-Roman times. By means of the combined use of X-ray diffraction (XRD), scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectrometry (EDS), selected-area X-ray photoelectron spectroscopy (XPS) and optical microscopy (OM), micro-chemical and micro-structural investigations have been carried out in order to identify the nature of the pyrometallurgical materials, to decipher the processes carried out there and their technological steps and to determine the technological level of competence reached by the ancient metallurgists. The results confirm that the findings can be associated with smelting and extractive processes carried out close to the metal ore deposits first for the argentiferous lead production and, then, for the silver recovery via a cupellation process. Finally, the results disclose the high level of technological competence of the ancient metallurgists able to carry out complex high-temperature processes to treat the argentiferous lead ores and to recover low amounts of silver via high-temperature lead-selective oxidation.

Archaeo-metallurgical studies of tuyeres and smelting slags found at Tharros (north-western Sardinia, Italy)

A large number of pyrometallurgical materials such as tuyeres, slags and refractory tools likely associated with metal extraction processes have been found at Tharros (north-western Sardinia, Italy) during archaeological excavations stratigraphically related to the Phoenician–Punic period (VI–III centuries BC). Micro-chemical, micro-structural and mineralogical studies have been carried out by means of the combined use of X-ray diffraction (XRD), selected-area X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) combined with energy-dispersive X-ray analysis (EDS) in order to identify pyrometallurgical processes and main relevant technological parameters. The results reveal that tuyeres, slags and refractory tools can be associated with an iron ore smelting process to extract the metal by slagging the unwanted by-products. Moreover, temperature and duration of the smelting process have been estimated through mineralogical studies and by a comparative analysis between the micro-chemical and structural features of thermally treated refractory materials and tuyeres. The results disclose the high level of technological competence of the ancient metallurgists able to carry out complex high-temperature processes to extract iron from ores by separating the metal from unwanted siliceous species.

Non-solvolytic synthesis of aqueous soluble TiO2 nanoparticles and real-time dynamic measurements of the nanoparticle formation.

Highly aqueously dispersible (soluble) TiO2 nanoparticles are usually synthesized by a solution-based sol–gel (solvolysis/condensation) process, and no direct precipitation of titania has been reported. This paper proposes a new approach to synthesize stable TiO2 nanoparticles by a non-solvolytic method - direct liquid phase precipitation at room temperature. Ligand-capped TiO2 nanoparticles are more readily solubilized compared to uncapped TiO2 nanoparticles, and these capped materials show distinct optical absorbance/emission behaviors. The influence of ligands, way of reactant feeding, and post-treatment on the shape, size, crystalline structure, and surface chemistry of the TiO2 nanoparticles has been thoroughly investigated by the combined use of X-ray diffraction, transmission electron microscopy, UV-visible (UV–vis) spectroscopy, and photoluminescence (PL). It is found that all above variables have significant effects on the size, shape, and dispersivity of the final TiO2 nanoparticles. For the first time, real-time UV–vis spectroscopy and PL are used to dynamically detect the formation and growth of TiO2 nanoparticles in solution. These real-time measurements show that the precipitation process begins to nucleate after an initial inhibition period of about 1 h, thereafter a particle growth occurs and reaches the maximum point after 2 h. The synthesis reaction is essentially completed after 4 h.

Nanostructures ofMg0.65Ti0.35Dxstudied with x-ray diffraction, neutron diffraction, and magic-angle-spinningH2NMR spectroscopy

Magnesium transition-metal alloys have a high hydrogen-storage capacity and show improved hydrogen-uptake and -release kinetics compared to magnesium alone. In the present study we have investigated the structure of bulk magnesium-titanium deuteride ${\text{Mg}}_{0.65}{\text{Ti}}_{0.35}{\text{D}}_{x}$ prepared via mechanical alloying and gas-phase deuterium absorption by combined use of x-ray diffraction (XRD), neutron diffraction, and magic-angle-spinning $^{2}\text{H}$ nuclear magnetic resonance (NMR). The initial ball-milled alloy has two XRD-distinct Mg and Ti fcc phases. Even after prolonged exposure to deuterium gas at 75 bar and $175\text{ }\ifmmode^\circ\else\textdegree\fi{}\text{C}$ the materials with and without palladium catalyst are only partly deuterated. Deuterium loading causes the formation of, on the one hand, bct (rutile) ${\text{MgD}}_{2}$ nanodomains with interdispersed ${\text{TiD}}_{y}$ layers and, on the other hand, a separate fcc (fluorite) ${\text{TiD}}_{z}$ phase. The ${\text{TiD}}_{y}$ phase is XRD invisible, but shows clearly up at a $^{2}\text{H}$ NMR shift of $\ensuremath{-}43\text{ }\text{ppm}$ between the shift of ${\text{MgD}}_{2}$ (3 ppm) and the Knight shift of the ${\text{TiD}}_{z}$ phase $(\ensuremath{-}143\text{ }\text{ppm})$. Exchange NMR indicates complete deuterium exchange at $25\text{ }\ifmmode^\circ\else\textdegree\fi{}\text{C}$ between the ${\text{MgD}}_{2}$ and ${\text{TiD}}_{y}$ phase within 1 s, as consistent with intimate contacts between these phases. Combined analysis of the XRD and NMR peak areas suggests that the deuterium concentrations $y$ and $z$ in the ${\text{TiD}}_{y}$ and ${\text{TiD}}_{z}$ domains are about 1.5 and 2.0, respectively. Comparing the intrinsic cell parameters of rutile ${\text{MgH}}_{2}$ and fluorite ${\text{TiH}}_{2}$, we propose that stabilization of the mixed nanocomposite may arise from a coherent coupling between the crystal structures of the rutile ${\text{MgD}}_{2}$ nanodomains and the thin layers of fcc ${\text{TiD}}_{y}$.

New opportunities for 3D materials science of polycrystalline materials at the micrometre lengthscale by combined use of X-ray diffraction and X-ray imaging

Non-destructive, three-dimensional (3D) characterization of the grain structure in mono-phase polycrystalline materials is an open challenge in material science. Recent advances in synchrotron based X-ray imaging and diffraction techniques offer interesting possibilities for mapping 3D grain shapes and crystallographic orientations for certain categories of polycrystalline materials. Direct visualisation of the three-dimensional grain boundary network or of two-phase (duplex) grain structures by means of absorption and/or phase contrast techniques may be possible, but is restricted to specific material systems. A recent extension of this methodology, termed X-ray diffraction contrast tomography (DCT), combines the principles of X-ray diffraction imaging, three-dimensional X-ray diffraction microscopy (3DXRD) and image reconstruction from projections. DCT provides simultaneous access to 3D grain shape, crystallographic orientation and local attenuation coefficient distribution. The technique applies to the larger range of plastically undeformed, polycrystalline mono-phase materials, provided some conditions on grain size and texture are fulfilled. The straightforward combination with high-resolution microtomography opens interesting new possibilities for the observation of microstructure related damage and deformation mechanisms in these materials.

Kinetic protein crystallography: a tool to watch proteins in action

Many proteins function in the crystalline state, making crystallography a tool that, beside structure, can address mechanism. By initiating biological turnover in the crystal, transient structural species form, which may be filmed ‘on the fly’ by Laue diffraction or captured by trapping methods. These strategies are jointly referred to as ‘kinetic crystallography’. In this article, we review the general concepts of kinetic crystallography in the context of the conformational energy landscape of a protein. Whereas Laue diffraction is best suited to the investigation of cyclic, ultra-fast and light-triggered reactions, trapping approaches, on the other hand, are applicable to a wider range of biological systems but require care to avoid artefacts. Complementary methods – mainly UV/visible single-crystal spectroscopy – have proven essential to design, interpret and validate kinetic crystallography experiments. Achievements in the field as well as remaining puzzling questions are considered through the examination of recently published work: real-time-resolved crystallography of dimeric haemoglobin based on pump-probe Laue diffraction, temperature-trapping crystallography of acetylcholinesterase based on photo- and radio-induced ligand cleavage, and lattice-trapping crystallography of superoxide reductase based on product soaking and the combined use of X-ray diffraction and Raman spectroscopy.

Structural and magnetic properties ofL10-FePt nanoparticles aligned by external magnetic field

We investigated structural and magnetic properties of the easy-axis aligned $L{1}_{0}$-FePt nanoparticles by the combined use of x-ray diffraction (XRD), magnetization, and $^{57}\text{F}\text{e}$ M\ossbauer measurements. The $L{1}_{0}$-FePt nanoparticles were fixed in a polystyrene matrix by performing free radical polymerization of styrene under an aligning external magnetic field. M\ossbauer spectrum of the $L{1}_{0}$-FePt nanoparticles/polystyrene composite showed tremendous decrease in the second and fifth absorption lines under the condition that the incident $\ensuremath{\gamma}$ ray was parallel to the aligning field. This result indicates that the easy axes of the $L{1}_{0}$-FePt nanoparticles in the composite have a strong preferred orientation with a finite distribution. We estimated the distribution of easy-axis orientation by using the M\ossbauer hyperfine parameters, which is in good agreement with that determined by the XRD rocking curve.

Quasicrystallization of (Zr&lt;sub&gt;65&lt;/sub&gt;Al&lt;sub&gt;7.5&lt;/sub&gt;Cu&lt;sub&gt;27.5&lt;/sub&gt;)&lt;sub&gt;95&lt;/sub&gt;Ti&lt;sub&gt;5&lt;/sub&gt; Glassy Alloy

Phase transformation in the melt-spun (Zr65Al7.5Cu27.5)95Ti5 glassy alloy was investigated by a combined use of X-ray diffraction (XRD), transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). It was found that the crystallization mode of the Zr65Al7.5Cu27.5 glassy alloy was altered by the addition of Ti, and nanometer scaled icosahedral phase (I-phase) formation was observed in the primary crystallization stage of the (Zr65Al7.5Cu27.5)95Ti5 quaternary glass, which transformed to the stable Zr2Cu-type phase upon further annealing. The crystallization behavior of (Zr65Al7.5Cu27.5)95Ti5 glass was further discussed in terms of the activation energy as compared to that of Zr65Al7.5Cu27.5 alloy.