The tongue is a fundamental organ in feeding, vocalization, and grooming. It is characterized by evolutionary adaptations reflected by diet, habitat, and function. Rodents are a very diverse mammalian order and the tongue's morphology varies in size, form, and presence of papillae. This work aimed to describe the morphological and ultrastructural aspects of the tongue of Spix's yellow-toothed cavy (Galea spixii, Wagler, 1831). Tongues of Spix's yellow-toothed cavies were analyzed with light microscopy, scanning, and transmission electron microscopy. The results showed that the tongue was divided into apex, body, and root. There were different types of papillae, such as vallate, foliate, laterally placed fungiform, fungiform, filiform, and robust filiform. The epithelium was organized into layers, including keratinized, granulous, spinous, and basal, below were lamina propria, and musculature, which evolved mucous and serous gland clusters. The tongue of Spix's yellow-toothed cavy was structurally and ultrastructurally similar to other rodents and had papillae with similar morphologies to other Caviidae species. However, the presence of robust filiform papillary lines and laterally placed fungiform papillae showed the main differences from other species. This was the first description of the tongue of Spix's yellow-toothed cavy.

Zr-based bulk metallic glasses (BMGs) are amorphous alloys that can exhibit excellent mechanical properties, including high yield strength and fracture toughness. These properties are linked to local microstructural heterogeneities. Whether via microscopy-based techniques, synchrotron techniques, or calorimetric approaches, the amorphous structure of BMGs makes the characterisation of the details of these local structural and chemical heterogeneities extremely challenging. Our focus here is on atom probe tomography (APT), where considerable uncertainty remains in terms of how and when to apply this otherwise powerful technique to amorphous materials. This work reports a systematic evaluation of the experimental parameter space. We report results of BMG composition acquired against various APT operating parameters for Zr63.96Cu13.36Ni10.29Al11.04Nb1.25 (at. %). We demonstrate that a customised peak-based ranging approach yields satisfactory compositional accuracy with absolute errors of <1 at. %. Beyond composition, we have discussed the data quality in terms of attributes of the mass spectra: mass resolution, signal-to-thermal tail ratio, and overlapped peak ratio. We also assess the composition of the well-known clustered evaporation effects, common in APT data of BMGs. We conclude that these regions have negligible differences in composition from the surrounding “matrix” or bulk in these alloys.

The unclear miscibility of CuNi alloys was investigated with atom probe tomography (APT). Multilayered thin film samples were prepared by ion beam sputtering (IBS) and focused ion beam (FIB) shaping. Long-term isothermal annealing treatments in a UHV furnace were conducted at temperatures of 573, 623, and 673 K to investigate the mixing process. The effective interdiffusion coefficient of the nanocrystalline microstructure (including defect diffusion) was determined to be Deff = 1.86 × 10−10 m2/s × exp(−164 kJ/mol/RT) by fitting periodic composition profiles through a Fourier series. In nonequilibrium states, microstructural defects like grain boundaries and precipitates were observed. While at the two higher temperatures total mixing is observed, a clear experimental evidence is found for a miscibility gap at 573 K with the boundary concentrations of 26 and 66 at%. These two compositions are used in a subregular solution model to reconstruct the phase miscibility gap. So, the critical temperature TC of the miscibility gap is found to be 608 K at a concentration of 45 at% Ni.

The intestinal bulb is a simple dilatation in the anterior part of the intestine of agastric fish. This study was conducted on 18 adult specimens of molly fish (Poecilia sphenops) and demonstrated the presence of an intestinal bulb. The intestinal epithelium was composed of enterocytes covered with microvilli, many mucous goblet cells, and enteroendocrine cells. Numerous intraepithelial lymphocytes, neutrophils, plasma cells, dendritic cells, stem cells, rodlet cells, and macrophages were identified in the epithelial layer. Interestingly, this study recorded the process of autophagy and formation of autophagosomes, multivesicular bodies, and dense bodies. The intestinal epithelium extended into the intestinal gland that consisted of simple columnar epithelium, mucous cells, stem cells, enteroendocrine cells, and basal cells. These glands opened to the lumen of the bulb and were surrounded by a network of telocytes. Moreover, immunohistochemistry revealed that the intestinal epithelium expressed APG5, myostatin, TGF-β, IL-1β, NF-κB, Nrf2, and SOX9. Leukocytes in the lamina propria-submucosa expressed APG5. The inflammatory cells in the connective tissue showed strong immunoreactivity to myostatin and TGF-β. The smooth muscular layer also expressed myostatin. Both IL-1β and NF-κB showed immunoreactivity in macrophages in the lamina propria-submucosa. Stem cells expressed Sox-9 and telocytes expressed NF-κB and SOX9; while astrocytes in the tunica muscularis expressed GFAP. The high frequency of immune cells in the intestinal bulb suggested an immune role of this organ. This is the first study demonstrating the absence of the stomach and its replacement with an intestinal bulb in molly fish, and consequently, this species could be reclassified as agastric fish according to this study.

The properties and the shape memory effect depend, among other things, on chemical composition, as well as the method of shape memory alloy (SMA) production. One of the manufacturing methods that leads to the amorphous/nanocrystalline SMA is high-energy ball milling combined with annealing. Using this technique, an SMA memory alloy, with the nominal chemical composition of Ni25Ti50Cu25, was produced from commercial elemental powders (purity −99.7%). The structure and morphology were characterized (at the various stages of its production) by the use of X-ray diffraction, as well as electron microscopy (both scanning and transmission). Choosing the appropriate grinding time made it possible to produce an NiTiCu alloy with a different crystallite size. Its average size changed from 6.5 nm (after 50 h) to about 2 nm (100 h). Increasing the grinding time up to 140 h resulted in the formation of areas that showed the B19 martensite and the Ti2(Ni,Cu) phase with the average crystallite size of about 6 nm (as milled). After crystallization, the average size increased to 11 nm.

The study of the fundamentals of the α → ω and β → ω phase transformations induced by high-pressure torsion (HPT) in Ti–Nb-based alloys is presented in the current work. Prior to HPT, three alloys with 5, 10, and 20 wt% of Nb were annealed in the temperature range of 700–540°C in order to obtain the (α + β)-phase state with a different amount of the β-phase. The samples were annealed for a long time in order to reach equilibrium Nb content in the α-solid solution. Scanning electron microscope (SEM), transmission electron microscopy, and X-ray diffraction techniques were used for the characterization of the microstructure evolution and phase transformations. HPT results in a strong grain refinement of the microstructure, a partial transformation of the α-phase into the ω-phase, and a complete β → ω phase transformation. Two kinds of the ω-phase with different chemical compositions were observed after HPT. The first one was formed from the β-phase, enriched in Nb, and the second one from the almost Nb-pure α-phase. It was found that the α → ω phase transformation depends on the Nb content in the initial α-Ti phase. The less the amount of Nb in the α-phase, the more the amount of the α-phase is transformed into the ω-phase.

The quantitative characterization of small nano-sized precipitates poses genuine challenges and is often deficient in accuracy due to the inherent limitations inevitably associated with the individual experimental techniques. A convenient solution is to utilize multiple complementary techniques. The present work demonstrates an effective way to reliably quantify nano-sized precipitates using a combination of complementary techniques of atom probe tomography (APT), small angle neutron scattering (SANS), and transmission electron microscopy (TEM). As a case study, the size (radius, r), number density (NP), volume fraction (ϕ), and chemical composition of Cr-rich α′ precipitates are determined in Fe–20 at% Cr alloy, thermally aged at 773 K for 1,000 h. This combinatorial approach utilizes the strength of each technique in such a way that the overall accuracy of quantitative precipitation analysis improves significantly. For example, the superior spatial resolution makes TEM the appropriate technique to estimate the size and size distribution of the precipitates, while APT provides the chemical composition. Similarly, SANS analysis incorporates both the size and the compositional information thus derived independently and provides statiscally averaged quantitative analysis overcoming the field-of-view limitations of both TEM and APT. This combinatorial approach improves the accuracy of quantification and provides the true representation of the microstructure.

In this study, binary as-cast Al–Cu alloys: Al25Cu (Al–25%Cu) and Al45Cu (Al–45%Cu) (in wt%) were severely plastically deformed by extrusion combined with a reversible torsion (KoBo) method to produce an ultrafine-grained structure (UFG). The binary Al–Cu alloys consist of α-Al and intermetallic Al2Cu phases. The morphology and volume fraction of α-Al and Al2Cu phases depend on the Cu content. The KoBo process was carried out using extrusion ratios of λ = 30 and λ = 98. The effect of phase refinement has been studied by means of scanning electron microscopy with electron backscattering diffraction and scanning transmission electron microscopy. The mechanical properties were assessed using compression tests. Detailed microstructural analysis shows that after the KoBo process, a large number fraction of high-angle boundaries (HABs) and a very fine grain structure (~2–4 μm) in both phases are created. An increase of λ ratio during the KoBo processing leads to a decrease in average grain size of α-Al and Al2Cu phases and an increase in fraction of HABs. UFG microstructure and high fraction of HABs provide the grain boundary sliding mechanism during KoBo deformation. UFG microstructure contributes to the enhanced mechanical properties. Compressive strength (Rc) of Al25Cu alloy increases from 172 to 340 MPa with an increase of λ. Compressive strain (Sc) for Al25Cu alloy increased from 35 to 67% with an increase of λ. High fraction of intermetallic phase in Al45Cu alloy was responsible for room temperature strengthening of alloy and low compressive strain. The deformed Al45Cu alloy with λ = 30 showed that Rc is 194 MPa and Sc is equal to 10%.

To solve the uncertainty of the platinum (Pt)–palladium (Pd) phase diagram, especially the existence of a suggested miscibility gap, atom probe tomography (APT) was used to determine the time evolution of the composition after heat treatment. Due to the extraordinarily slow diffusion in the temperature range of the controversial phase separation, the investigated volume was limited to nano-sized multiple layers deposited by ion beam sputtering (IBS). The evaporated volume was reconstructed from the obtained datasets and the respective diffusion coefficients were determined using the Fourier series solution of the diffusion equation. Beginning with pure Pt and Pd layers annealed at 673, 773, 873, and 973 K, the mixing appears to be purely diffusion controlled in the chosen annealing times, but the state of complete mixing was still not observed. Therefore, extended isothermal annealing sequences at 673 and 773 K with pre-alloyed layers have been carried out. They clearly suggest complete mixing even at the lowest investigated temperatures.

Rapidly solidified alloys with a nominal composition of Al76.5Fe23.5 and Al75.8Co24.2 (in at%), corresponding to the Al13Fe4 and Al13Co4 phases, were produced by a melt spinning technique. The microstructure and phase composition of the as-spun and heat-treated ribbons were examined by X-ray diffraction, scanning and transmission electron microscopy. The as-spun ribbons consisted of columnar grains with an average size of 1–2 μm, which increased by a factor of 2 after applied heat treatment. The Al13Fe4 as-spun ribbon comprised of two phases: grains of the Al13Fe4 phase surrounded by solid solution of Al, transformed into a single monoclinic Al13Fe4 phase after annealing. The as-spun Al13Co4 ribbons had a multiphase structure. A decagonal quasicrystalline D-phase, the monoclinic M-Al13Co4 phase, and the Al9Co2 phase were identified in their microstructure. After the heat treatment, the mixture of the orthorhombic O-Al13Co4 phase and grains of monoclinic Y-Al13Co4 were observed. The investigations of catalytic properties were performed for the phenylacetylene hydrogenation reaction using pulverized ribbons in the initial state and after annealing. The degree of conversion was in the range of 8–27% and increased with the increasing reaction temperature. The highest selectivity to styrene was obtained for the Al13Fe4 alloy in the as-spun state.

Sub-10 nm ferroelectric and multiferroic materials are attracting increased scientific and technological interest, owing to their exciting physical phenomena and prospects in miniaturized electronic devices, neuromorphic computing, and ultra-compact data storage. The Bi6Ti2.9Fe1.5Mn0.6O18 (B6TFMO) Aurivillius system is a rare example of a multiferroic that operates at room temperature. Since the formation of magnetic impurity phases can complicate attempts to measure ferromagnetic signal intrinsic to the B6TFMO multiferroic phase and thus limits its use, herein we minimize this by utilizing relatively large (49%) bismuth excess to counteract its volatility during sub-10 nm growth. X-ray diffraction, electron microscopy, and atomic force microscopy show sample crystallinity and purity are substantially improved on increasing bismuth excess from 5 to 49%, with the volume fraction of surface impurities decreasing from 2.95–3.97 vol% down to 0.02–0.31 vol%. Piezoresponse force microscopy reveals 8 nm B6TFMO films are ferroelectric, with an isotropic random distribution of stable in-plane domains and weaker out-of-plane piezoresponse. By reducing the volume fraction of magnetic impurities, this work demonstrates the recent progress in the optimization of ultra-thin B6TFMO for future multiferroic technologies. We show how the orientation of the ferroelectric polarization can be switched in 8 nm B6TFMO and arrays can be “written” and “read” to express states permitting anti-parallel information storage.

Melt-spun Ni70Ga30 and Ni70Sn30 monolithic catalysts, when subjected to prolonged oxidation in air at 770 K, undergo different microstructural changes. Whereas Ni70Ga30 is largely stable and composed of Ni3Ga phase, the Ni70Sn30 develops a two-layer microstructure on the exposed ribbon surface. The two-layer structure consists of a Ni-rich zone, which is founded on a SnO2 sublayer. In the bulk, the Ni70Sn30 ribbon is heterogeneous in phase composition and comprises of Ni3Sn and Ni3Sn2 phases. The development of Ni particulates on the outer ribbon surface, through simple oxidation heat treatment, may thus be a way for improving the catalytic performance of Ni70Sn30 ribbons, resembling that of Ni3Al ribbons spontaneously activated under reaction conditions.

In recent years, atomic resolution imaging of two-dimensional (2D) materials using scanning transmission electron microscopy (STEM) has become routine. Individual dopant atoms in 2D materials can be located and identified using their contrast in annular dark-field (ADF) STEM. However, in order to understand the effect of these dopant atoms on the host material, there is now the need to locate and quantify them on a larger scale. In this work, we analyze STEM images of MoS2 monolayers that have been ion-implanted with chromium at ultra-low energies. We use functions from the open-source TEMUL Toolkit to create and refine an atomic model of an experimental image based on the positions and intensities of the atomic columns in the image. We then use the refined model to determine the likely composition of each atomic site. Surface contamination stemming from the sample preparation of 2D materials can prevent accurate quantitative identification of individual atoms. We disregard atomic sites from regions of the image with hydrocarbon surface contamination to demonstrate that images acquired using contaminated samples can give significant atom statistics from their clean regions, and can be used to calculate the retention rate of the implanted ions within the host lattice. We find that some of the implanted chromium ions have been successfully integrated into the MoS2 lattice, with 4.1% of molybdenum atoms in the transition metal sublattice replaced with chromium.