Crystallographic Point Of View Research Articles

Surface morphology of naphtacene single crystals grown by the physical vapor transport technique

The surface morphology of naphtacene single crystals grown by the physical vapor transport technique was investigated by atomic force microscopy and white-beam X-ray topography. Locally, two types of line pattern were observed on the basal (001) plane along the [110] and [010] directions, and analyzed from crystallographic viewpoints. Such line patterns are considered in relation to crystallographic periodicities, dislocation lines, and slip-plane phenomena.

High-pressure intrusion of double salt aqueous solution in pure silica chabazite: searching for cation selectivity

Heterogeneous lyophobic systems (HLSs), i.e. systems composed of a nanoporous solid and a non-wetting liquid, have attracted much attention as promising candidates for innovative mechanical energy storage and dissipation devices. In this work, a new HLS based on a pure silica chabazite (Si-CHA) and a ternary electrolyte solution (KCl + CaCl2) is studied from porosimetric and crystallographic points of view. The combined approach of this study has been fundamental in unravelling the properties of the system. The porosimetric experiments allowed the determination of the energetic behaviour, while high-pressure in situ crystallographic analyses helped elucidate the mechanism of intrusion. The results are compared with those obtained for systems involving the same zeolite but intruded with solutions containing only single salts (CaCl2 or KCl). The porosimetric results of the three Si-CHA systems intruded by simple and complex electrolyte solutions (KCl 2 M, CaCl2 2 M and the mixture KCl 1 M + CaCl2 1 M) suggest that the intrusion pressure is mainly influenced by the nature of the cations. The CaCl2 2 M solution shows the highest intrusion pressure and KCl 2 M the lowest, whereas the mixture KCl 1 M + CaCl2 1 M is almost in the middle. These differences are probably related to the higher hydration enthalpy and Gibbs energy of Ca2+ compared with those of K+. It has been demonstrated that partial ion desolvation is needed to promote the penetration of the species, and a higher solvation energy requires higher pressure. The `intermediate' value of intrusion pressure shown by the complex electrolyte solution arises from the fact that, statistically, the second/third solvation cation shells can be assumed to be partially shared between K+ and Ca2+. The stronger interaction of Ca2+ with H2O molecules thus also influences the desolvation of K+, increasing the pressure needed to activate the process compared with the pure KCl 2 M solution. This is confirmed by the structural investigation, which shows that at the beginning of intrusion only K+, Cl− and H2O penetrate the pores, whereas the intrusion of Ca2+ requires higher pressure, in agreement with the hydration enthalpies of the two cations.

Anomalous Hall Transport by Optically Injected Isospin Degree of Freedom in Dirac Semimetal Thin Film.

Chirality of massless fermions emerging in condensed matter is a key to understand their characteristic behavior as well as to exploit their functionality. However, the chiral nature of massless fermions in Dirac semimetals has remained elusive, due to equivalent occupation of carriers with the opposite chirality in thermal equilibrium. Here, we show that the isospin degree of freedom, which labels the chirality of massless carriers from a crystallographic point of view, can be injected by circularly polarized light. Terahertz Faraday rotation spectroscopy successfully detects the anomalous Hall conductivity by a light-induced isospin polarization in a three-dimensional Dirac semimetal, Cd3As2. Spectral analysis of the Hall conductivity reveals a long scattering time and a long decay time, which are characteristic of the isospin. The long-lived, robust, and reversible character of the isospin promises a potential application of Dirac semimetals in future information technology.

First-Principles Calculation of MoO2 and MoO3 Electronic and Optical Properties Compared with Experimental Data.

MoO3 and MoO2 systems have attracted particular attention for many widespread applications thanks to their electronic and optical peculiarities; from the crystallographic point of view, MoO3 adopts a thermodynamically stable orthorhombic phase (α-MoO3) belonging to the space group Pbmn, while MoO2 assumes a monoclinic arrangement characterized by space group P21/c. In the present paper, we investigated the electronic and optical properties of both MoO3 and MoO2 by using Density Functional Theory calculations, in particular, the Meta Generalized Gradient Approximation (MGGA) SCAN functional together with the PseudoDojo pseudopotential, which were used for the first time to obtain a deeper insight into the nature of different Mo-O bonds in these materials. The calculated density of states, the band gap, and the band structure were confirmed and validated by comparison with already available experimental results, while the optical properties were validated by recording optical spectra. Furthermore, the calculated band-gap energy value for the orthorhombic MoO3 showed the best match to the experimental value reported in the literature. All these findings suggest that the newly proposed theoretical techniques reproduce the experimental evidence of both MoO2 and MoO3 systems with high accuracy.

Characterization of tin-plated steel

Tinplating on steel is a useful industrial process extensively used for food packaging. Cold-rolled annealed steel coated with tin gives the steel corrosion resistance property and a beautiful luster. Tinplating on steel is a complex process where rolled and annealed steel sheets are cleaned with acid to remove rust, grease, or oil from the surface. Pure tin is electrodeposited on this freshly prepared surface after the electrodeposition of tin on the steel strip; the surface becomes lustrous, the color of pure tin appears, and the finish is called matte. Very often, the flowing heat treatment is just about the tin melting point of 232°C–265°C. After electrodeposition, pure tin deposits on the steel surface; however, a chemical reaction between tin and iron occurs during the brightening treatment. This process results in iron–tin intermetallic formation; their orientation grain structure and orientation of substrate steel all have a synergistic effect on the final properties of tin-coated steel. In the present study, an attempt has been made to study this parameter in detail. A total of five commercially produced tin-plated steel have been selected for the present purpose, and both tin coating and substrate steel have been thoroughly characterized by optical microscopy, scanning electron microscopy, X-ray diffraction (XRD), and the crystallographic texture point of view; however, the best result has been discussed in this paper. The different phases of tin and the iron–tin compound have been identified using XRD, X-ray, and a texture goniometer that are used to find out the crystallographic texture observed in the presence of FeSn2, FeSn, and Sn in tin coating; the volume fraction of these phases is observed to vary from one sample to another. This variation may affect tinplating steel’s final property, which can be studied in the future work.

Impact of Post-Synthesis heat treatment avoidance on cobalt carbonate hydroxide as a Battery-Type electrode material

In this study, the electrochemical energy storage properties of one-dimensional (1D) hierarchical nanowire array (NWA) of cobalt carbonate hydroxide hydrate (Co6(CO3)2(OH)8·H2O) (CCH) is explored. The 1D nanostructure is advantageous due to their better charge/ion transport properties. The material was synthesized via. simple, and facile hydrothermal approach. The highlighting feature of this work lies in its post-synthesis process, where the authors deliberately avoided the post-synthesis heat treatment process to utilize the hydrated (x‧H2O) part associated with the lattice water which eventually led CCH in a unique robust crystal structure. Here, the authors have explored multifaceted aspects of 1D CCH NWAs, including the nanowire synthesis, their growth mechanism, and pseudocapacitive charge storage properties. The authors propose a novel charge storage mechanism, insertion pseudocapacitance, which depends on the (de)intercalation of cations (e.g., Li+, Na+, K+, and H+), where tunnels play a significant role in charge storage properties. In this type of charge-storage mechanism, cationic diffusion occur from the interior of the crystalline framework along with the surface-confined phenomena. The electrochemical energy storage performance in terms of specific capacity (Csp) is found to be 243.55 mAhg−1 @ 5 mVs−1 scan rate and 161.465 mAhg−1 at 2500 mAg−1 current density. The material exhibited excellent capacity retention of ∼ 95 % and ∼ 86 % at significantly higher current densities of 20,000 mAg−1 and 100,000 mAg−1, respectively. This work tries to establish the structure-electrochemical property correlation of the CCH which has an exceptional crystal structure that is deduced ∼ 20 years after its first report. Therefore, the authors emphasize exploring the fundamental understanding of the CCH from the crystallographic point of view and its relevance to electrochemical energy storage. This work will help in exploring the next-generation metal carbonate hydroxide hydrate-based (MCH) materials.

MAl4Ir2 (M = Ca, Sr, Eu): superstructures of the KAu4In2 type

Three new iridium aluminum intermetallics CaAl4Ir2, SrAl4Ir2, and EuAl4Ir2 were synthesized from the elements using silica or tantalum ampoules. They crystallize in the tetragonal crystal system with space group P4/ncc and lattice parameters of a = 782.20(1) and c = 779.14(2) pm for CaAl4Ir2, a = 797.62(1) and c = 772.75(2) pm for SrAl4Ir2, and finally a = 791.78(5) and c = 773.31(5) pm for EuAl4Ir2. All compounds crystallize isostructurally and adopt a new structure type that can be derived from the KAu4In2 type structure. To compare the structures from a crystallographic point of view, a group–subgroup relation between KAu4In2 and EuAl4Ir2 as well as KAu4In2 and KAu4Sn2 have been established using the Bärnighausen formalism. Finally, quantum-chemical calculations have been conducted, showing that in all three title compounds, a polyanionic [Al4Ir2]δ– network exists with significant (polar) bonding interactions, while the respective Caδ+, Srδ+, and Euδ+ cations are located in octagonal channels.Graphical abstract

Surface oxidization effect on the mechanical behavior of aluminum nanopowders under triaxial compression test

In this paper, the impression of surface oxidization on the aluminum nanopowders is investigated using the reactive molecular dynamics (MD) method under the triaxial compression tests. Validation of the computational model is examined with the experimental results, which demonstrates an acceptable accuracy of the numerical simulations. The MD simulations are performed in three stages; relaxing the nanopowders at 300 K and 0.1 MPa, confining the nanopowders under hydrostatic pressure, and imposing the deviatoric stress through the triaxial compression. Evolutions of the relative density with pressure, stress with strain, and dislocation density with strain are derived together with the distributions of the radial distribution function and the pressure contours to characterize the mechanical behavior of nanopowders during the compression tests. The effect of the oxide shell thickness of the nanopowders at different compression paths is studied from the mechanical and crystallographic points of view. The results highlight that the hardness of nanopowders increases, and its ductility decreases as the oxide shell thickness increases. The microstructural analysis demonstrates that the crystalline structure of the alumina shell changes mainly during the hydrostatic pressure, while the crystalline structure of the aluminum core is primarily affected during the triaxial compaction.

Polarized Raman Scattering of In‐Plane Anisotropic Phonon Modes in α‑MoO3

AbstractThe recent discovery of in‐plane hyperbolic phonon polaritons in biaxial polar crystal—α‐MoO3, has aroused a huge research upsurge on anisotropic photonic quasiparticles in van der Waals materials. The physical origin of these highly anisotropic phonon polaritons is attributed to the strong anisotropy of crystal phonons. However, the orientation‐dependent phonon modes have not been fully understood from crystallographic point of view. This work systematically performs in situ angle‐resolved polarized Raman spectroscopy on α‐MoO3 to investigate its anisotropic photo‐phonon interactions. The sample orientation and Raman tensors are unambiguously determined under different polarization configurations. Specifically, the in‐plane anisotropic phonon modes of α‐MoO3 can be well characterized from the highly polarization‐dependent Raman‐active modes with periodic intensity variation. It can be concluded that these findings cannot only offer a better understanding of anisotropic phonon modes in α‐MoO3, but also provide a valuable reference for other anisotropic van der Waals crystals.

Crystallographic Calculations and First-Principles Calculations of Heterogeneous Nucleation Potency of γ-Fe on La2O2S Particles.

Rare earth (RE) inclusions with high melting points as heterogeneous nucleation in liquid steel have stimulated many recent studies. Evaluating the potency of RE inclusions as heterogeneous nucleation sites of the primary phase is still a challenge. In this work, the edge-to-edge matching (E2EM) model was employed to calculate the atomic matching mismatch and predict the orientation relationship between La2O2S and γ-Fe from a crystallographic point of view. A rough orientation relationship (OR) was predicted with the minimum values of and as follows: ∥ and ∥. The interface energy and bonding characteristics between La2O2S and γ-Fe were calculated on the atomic scale based on a crystallographic study using the first-principles calculation method. The calculations of the interface energy showed that the S-terminated and La(S)-terminated interface structures were more stable. The results of difference charge density, electron localization function (ELF), the Bader charges and the partial density of states (PDOS) study indicated that the La(S)-terminated interface possessed metallic bonds and ionic bonds, and the S-terminated interface exhibited metallic bond and covalent bond characteristics. This work addressed the stability and the characteristics of the La2O2S/γ-Fe interface structure from the standpoint of crystallography and energetics, which provides an effective theoretical support to the study the heterogeneous nucleation mechanism. As a result, La2O2S particles are not an effective heterogeneous nucleation site for the γ-Fe matrix from crystallography and energetics points of view.

X-ray molecular orbital analysis. II. Application to diformohydrazide, (NHCHO)2.

The molecular orbitals (MOs) of diformohydrazide have been determined from the electron density measured by X-ray diffraction. The experimental and refinement procedures are explained in detail and the validity of the obtained MOs is assessed from the crystallographic point of view. The X-ray structure factors were measured at 100 K by a four-circle diffractometer avoiding multiple diffraction, the effect of which on the structure factors is comparable to two-centre structure factors. There remained no significant peaks on the residual density map and the R factors reduced significantly. Among the 788 MO coefficients, 731 converged, of which 694 were statistically significant. The C-H and N-H bond distances are 1.032 (2) and 1.033 (3) Å, respectively. The electron densities of theoretical and experimental MOs and the differences between them are illustrated. The overall features of the electron density obtained by X-ray molecular orbital (XMO) analysis are in good agreement with the canonical orbitals calculated by the restricted Hartree Fock (RHF) method. The bonding-electron distribution around the middle of each bond is well represented and the relative phase relationships of the π orbitals are reflected clearly in the electron densities on the plane perpendicular to the molecular plane. However, differences are noticeable around the O atom on the molecular plane. The orbital energies obtained by XMO analysis are about 0.3 a.u. higher than the corresponding canonical orbitals, except for MO10 to MO14 which are about 0.7 a.u. higher. These exceptions are attributed to the N-H...O'' intermolecular hydrogen bond, which is neglected in the MO models of the present study. The hydrogen bond is supported by significant electron densities at the saddle points between the H(N) and O'' atoms in MO7, 8, 14 and 17, and by that of O''-p extended over H(N) in MO21 and 22, while no peaks were found in MO10, 11, 13 and 15. The electron density of each MO clearly exhibits its role in the molecule. Consequently, the MOs obtained by XMO analysis give a fundamental quantum mechanical insight into the real properties of molecules.

Triangular Interchalcogen Interactions: A Joint Crystallographic Data Analysis and Theoretical Study.

Noncovalent chalcogen-chalcogen interactions are being actively investigated from both crystallographic and theoretical viewpoints in recent years. According to our search of the Cambridge Structural Database (CSD), a huge number of crystal structures containing triangular Ch3 synthons were extracted. On the basis of the results of the CSD survey, a series of trimeric complexes of organic divalent chalcogen molecules were selected to model such interaction motifs. Similar to that in conventional chalcogen bonds, triangular interchalcogen interactions become gradually stronger along the sequence of Ch = S, Se, Te. Particularly, hydrogen bonds between the chalcogen centers and the H atoms in the substituents occur, which play a significant role in stabilizing the Ch3 motifs in the trimers. Through multibody energy calculations, the complexes under study exhibit no or only weak cooperativity. Finally, the differences between the Ch3 interaction motifs and the well-studied windmill X3 bonding (X means halogen and this is halogen bond) patterns were elucidated.

Peritectic reaction during directional solidification in a Ru-containing nickel-based single crystal superalloy

Abstract The peritectic reaction L + β-NiAl → γ′ during directional solidification in a Ru-containing nickel-based single crystal superalloy was investigated by the planar interface solidification and the phase transformation process was clarified in detail. The phase transformation mechanism of the peritectic reaction was further studied in the combination of the transmission electron microscope and the edge-to-edge matching model from the crystallographic point of view. The results indicated that the relaxation of some atoms on the matching planes (1 1 0)β and (1 1 1)γ′ maximized the atomic matching at the interface, increasing the possibility of peritectic γ′ phase nucleated on primary β-NiAl phase in the peritectic reaction.

Methyl transfer reactions catalyzed by cobalamin-dependent enzymes: Insight from molecular docking

Methyl transfer reactions, mediated by methyltransferases (MeTrs), such as methionine synthase (MetH) or monomethylamine: CoM (MtmBC), constitute one of the most important classes of vitamin B12-dependent reactions. The challenge in exploring the catalytic function of MeTrs is related to their modular structure. From the crystallographic point of view, the structure of each subunit has been determined, but there is a lack of understanding of how each subunit interacts with each other. So far, theoretical studies of methyl group transfer were carried out for the structural models of the active site of each subunit. However, those studies do not include the effect of the enzymatic environment, which is crucial for a comprehensive understanding of enzyme-mediated methyl transfer reactions. Herein, to explore how two subunits interact with each other and how the methyl transfer reaction is catalyzed by MeTrs, molecular docking of the functional units of MetH and MtmBC was carried out. Along with the interactions of the functional units, the reaction coordinates, including the Co–C bond distance for methylation of cob(I)alamin (CoICbl) and the C–S bond distance in demethylation reaction of cob(III)alamin (CoIIICbl), were considered. The functional groups should be arranged so that there is an appropriate distance to transfer a methyl group and present results indicate that steric interactions can limit the number of potential arrangements. This calls into question the possibility of SN2-type mechanism previously proposed for MeTrs. Further, it leads to the conclusion that the methyl transfer reaction involves some spatial changes of modules suggesting an alternate radical-based pathway for MeTrs-mediated methyl transfer reactions. The calculations also showed that changes in torsion angles induce a change in reaction coordinates, namely Co–C and C–S bond distances, for the methylation and demethylation reactions catalyzed both by MetH and MtmBC.

Effects of Cation-Disordering in Si4+- Substituted Li3VO4 As a Negative Electrode for Superredox Capacitors

Introduction SuperRedox Capacitors (SRC) that combine ultrafast pseudocapacitive battery materials as positive and negative electrodes are novel energy storages with battery-like energy density and supercapacitor-like power density and durability[1]. β-Li3VO4 (LVO) shows promising characteristics as a negative electrode for SRC with regards to its high energy density, with a specific capacity of 394 mAh g-1 (two electrons reaction). In addition, LVO reacts at potentials between 0.4 and 1.3 V vs. Li+/Li, whose range is suitable for the safe operation while achieving high cell voltage[2]. We have reported that disordering all cations-orientation (Li+ and V5+) of LVO increases Li+ diffusion coefficient (D Li) from the pristine LVO by a factor of one hundred, thus facilitating faster charge/discharge reactions[3]. However, such a cation-disordered structure has durability issues because of its thermodynamic metastability over 400˚C.In this study, we introduce a novel method to enhance Li+ conductivity of LVO while maintaining a stable structure. In order to obtain the same effect of cation-disordering, not all cations but only V5+ orientation was disordered by random substitution of V5+ with Si4+. Higher thermodynamic stability over 800˚C was achieved by maintaining specific arrangement between Li+ and Mn+ (Mn+ = V5+ or Si4+). Detailed influential factors of Si4+-substitution to electrochemical performances were discussed from the crystallographic point of view. Experimental Si4+-substituted LVO was prepared by a simple powder calcination process. V2O5, Li2CO3 and SiO2 powder were sealed in a zirconia pod of a planetary ball mill (PL-7, Fritsch) and mixed them at 300 rpm for 30 min. Mixture was calcined to obtain Li3+xV1-xSixO4 (LVSiO, 0≦x≦0.4). Characterization of the crystal structure was performed using X-ray and neutron diffraction techniques. In order to estimate D Li+ in the crystal structure, we used a Galvanostatic Intermittent Titration Technique (GITT). Electrochemical performances were measured using 2032-type coin cells assembled of LVSiO and Li metal electrodes. The used electrolyte composition was a 1.0 M solution of lithium hexafluorophosphate (LiPF6) dissolved in a mixture of ethylene carbonate and diethyl carbonate (50:50 in volume ratio). Results and Discussion Si4+-substituted LVO (LVSiO) was successfully synthesized, as confirmed by both X-ray and neutron diffraction patterns, confirming crystal phase change from a β-phase (Pnm21) of pristine LVO into a high-temperature γ-phase (Pnma) of LVSiO. Rietveld analysis revealed that Si4+ randomly occupied V5+ sites, whereas, Li+ and Mn+ (M = V5+ or Si4+) arrangements were maintained. Thermal stability was confirmed by in situ powder X-ray diffraction measurements while raising temperature in Ar atmosphere; the LVSiO crystal structure remains stable up to 800ºC.Results obtained from GITT measurements showed that D Li+ was maximized at 20 at.% of Si4+ and the value was maintained up to 40 at.% (Fig. 1). The effect of Si4+ substitution on reaction mechanisms were analyzed by in situ XRD electrochemical cell measurements by comparing the crystallographic change of LVO and LVSiO while Li+ insertion/deinsertion. The obtained results confirm that LVO reacts in two-phase separated mechanism and LVSiO reacts in solid solution mechanism, which is similar changes observed in the cation-disordered LVO[2,3]. It is considered that Li+ can diffuse more smoothly in solid solution mechanism than two-phase separated mechanism, since there is no phase boundary that disturbs diffusion of Li+. The D Li+ enhancement contributed to the improved capacity retention at a high rate of 100C from 25% (LVO) to 65% (LVSiO, Si20%). The obtained results show that the improvements of D Li+ and rate capability by Si4+-substitution can be achieved, as similar effect from a fully cation-disordering, while increasing thermodynamic stability. This study suggests that the main factor of effects of cation-disordering was due to the partially disordered orientation of transition metal (V5+, Si4+) cations without Li+.

Anatase Forming Treatment without Surface Morphological Alteration of Dental Implant.

The osseointegration of titanium implants is allowed by the TiO2 layer that covers the implants. Titania can exist in amorphous form or in three different crystalline conformations: anatase, rutile and brookite. Few studies have characterized TiO2 covering the surface of dental implants from the crystalline point of view. The aim of the present study was to characterize the evolution of the TiO2 layer following different surface treatments from a crystallographic point of view. Commercially pure titanium and Ti-6Al-4V implants subjected to different surface treatments were analyzed by Raman spectroscopy to evaluate the crystalline conformation of titania. The surface treatments evaluated were: machining, sandblasting, sandblasting and etching and sandblasting, etching and anodization. The anodizing treatment evaluated in this study allowed to obtain anatase on commercially pure titanium implants without altering the morphological characteristics of the surface.

Crystallographic analysis of fatigue fracture initiation in 8Ni-0.1C martensitic steel

The present paper investigated characteristics of fatigue fracture behavior, particularly initiation stage of fatigue fracture (Stage I), in an as-quenched martensitic steel from microstructural and crystallographic points of view. The detailed crystallographic orientation analysis using EBSD revealed that block boundaries in lath martensite structure were the most preferential initiation sites for fatigue cracks. We found that incompatibility of plastic strains between adjacent blocks was the origin for the formation of initial fatigue cracks at block boundaries. Moreover, plastic deformation along {011} slip planes also played an important role on the transgranular crack propagation.

Electronic and optical properties of graphene/molybdenite bilayer composite

Since its discovery, graphene has been the object of study for several and manifold applications, ranging from photocatalysis to mechanics and electronics of materials. However, the use of pure graphene in certain opto- and microelectronic applications is sometimes limited because of its zero band gap. Among the different methods to widen the band gap, in the present work the attention is focused on the so-called van der Waals composites (or heterostructures, or heterojunctions), namely the stacking of two monolayers of different materials that are held together by weak van der Waals interactions. An interesting composite is the graphene/molybdenite (MoS2) heterostructure, where the second material is a bidimensional semiconductor characterized by strong in-plane covalent bonds and weak out-of-plane interactions, which means that it is possible to exfoliate MoS2 into monolayers of atomic thickness. Also, from the crystallographic point of view, both graphene and the monolayer of molybdenite (MoS2-1H) have a 2D hexagonal lattice and their stacking could be structurally favourable. In this work, the electronic band structure and density of states, complex dielectric function and optical properties of the stacked van der Waals bilayer heterojunction graphene/MoS2-1H were calculated and compared to both the single monolayers of graphene and molybdenite, to understand how the interaction between the two materials may alter the above cited properties. The analysis of the band structure in this van der Waals composite clearly showed a small direct band gap related to the transition π→π∗ (ca. 2.5 meV) in correspondence of the high symmetry point K. The heterojunction showed also, as expected, some important variations in the complex dielectric function and related properties in the visible-light spectral region. The results obtained in the present work could be of use for future development and applications of this kind and similar 2D composite materials with tailored electronic and optical properties.

Acicular ferrite nucleation and growth in API5L-X65 steel submerged arc welded joints

In the present study, acicular ferrite nucleation and growth were investigated from a crystallographic point of view in API5L-X65 steel weld metals. It was observed that acicular ferrite was nucleated on inclusions in weld metal. The titanium-enriched layer around inclusions was characterised as the TiO phase by selected area diffraction patterns. A scanning electron microscope equipped with an electron backscatter diffraction technique was applied to investigate the crystallographic orientation relationship. The results showed that acicular ferrite lathes had a Baker–Nutting orientation relationship with the TiO layer on the inclusion surface in the nucleation of acicular ferrite. However, it is confirmed that the growth of acicular ferrite lathes depends on the deviation from the Kurdjumov–Sachs relationship between lathes and primary austenite.

Development of Crystallinity of Triclinic Polymorph of Tricalcium Silicate.

Tricalcium silicate phase is one of the main components of modern Portland cements. One of the major industrial challenges in the field of cement production is mapping the influence of individual clinker minerals and their polymorphs on the properties of industrially produced clinkers. The primary goal of this work is to improve the fundamental knowledge of understanding the process of alite formation and development from a crystallographic point of view. This study focuses on the observation of the crystallization process of triclinic alite during the firing process, which to date has not been thoroughly described. The effects of a wide range of temperatures and sintering periods on crystallinity were assessed on samples fired in platinum crucibles in a laboratory furnace. X-ray analysis—together with calculation of crystallinity using Scherrer’s equation—was used for observing the crystallite size changes of T1 alite polymorph. According to the acquired results, among the most technologically and economically advantageous regimes of production of a high-quality triclinic alite is the temperature of 1450 °C and sintering time of two hours. The most significant changes in the crystallite size occurred within the first hour of sintering for the whole investigated temperature range.