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We have investigated the electronic transport properties of resistivity, magnetoresistance and the Hall effect on epitaxial and polycrystalline Fe3Si thin films. The electrical transport measurements reveal the microstructure which has not been clarified from x-ray diffraction and/or scanning electron microscopy. We show that (1 0 0)-oriented epitaxial film 36 nm thick on MgO(1 1 1) exhibits ferromagnetic-tunnelling conduction, (1 1 0)-oriented epitaxial film 36 nm thick on yttria stabilized zirconia [YSZ(1 1 1)] is in a percolated region, and polycrystalline film 36 nm thick on Al2O3(1 1 0) and (1 0 0)-oriented epitaxial film 150 nm thick on MgAl2O4(1 0 0) have metallic conduction. These results imply that the electrical transport measurements are a powerful tool for evaluating the microstructure of the samples. The coefficients of the skew and the side-jump scatterings in the extraordinary Hall effect, and the quadratic temperature coefficient of resistivity observed on (1 0 0)-oriented epitaxial film 150 nm thick on MgAl2O4 show that Fe3Si is a ferromagnetic metal where the effective electron mass is slightly enhanced compared with Fe, Co and Ni due to the electron-electron correlation. [ABSTRACT FROM AUTHOR]

Scientific advancement is universally based on the dynamic interplay between theoretical insights, modeling, and experimental discoveries. However, this feedback loop is often slow, including delayed community interactions and the gradual integration of experimental data into theoretical frameworks. This challenge is particularly exacerbated in domains dealing with high-dimensional object spaces, such as molecules and complex microstructures. Hence, the integration of theory within automated and autonomous experimental setups, or theory in the loop-automated experiment, is emerging as a crucial objective for accelerating scientific research. The critical aspect is to use not only theory but also on-the-fly theory updates during the experiment. Here, we introduce a method for integrating theory into the loop through Bayesian conavigation of theoretical model space and experimentation. Our approach leverages the concurrent development of surrogate models for both simulation and experimental domains at the rates determined by latencies and costs of experiments and computation, alongside the adjustment of control parameters within theoretical models to minimize epistemic uncertainty over the experimental object spaces. This methodology facilitates the creation of digital twins of material structures, encompassing both the surrogate model of behavior that includes the correlative part and the theoretical model itself. While being demonstrated here within the context of functional responses in ferroelectric materials, our approach holds promise for broader applications, such as the exploration of optical properties in nanoclusters, microstructure-dependent properties in complex materials, and properties of molecular systems.

Since the discovery of ferroelectricity in a wurtzite-type structure, this structural type has gathered much attention as a next-generation ferroelectric material due to its high polarization value combined with its high breakdown strength. However, the main targets of wurtzite-type ferroelectrics have been limited thus far to simple nitride/oxide compounds. The investigation of new ferroelectric materials with wurtzite-type structures is important for understanding ferroelectricity in such structures. We therefore focus on β-LiGaO 2 in this study. Although AlN and ZnO possess well-known wurtzite-type structures ( P 6 3 mc ), β-LiGaO 2 has a distorted wurtzite-type structure ( Pna 2 1 ), and there are no reports of ferroelectricity in LiGaO 2 . In this study, we have revealed that LiGaO 2 exhibits relatively high barrier height energy for polarization switching, however, Sc doping effectively reduces that energy. Then, we conducted thin film preparation and evaluation for Sc-doped LiGaO 2 to observe its ferroelectric properties. We successfully observed ferroelectric behavior by using piezoresponse force microscopy measurements for LiGa 0.8 Sc 0.2 O 2 /SrRuO 3 /(111)SrTiO 3 ., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Tetragonal (1- x )(Bi,Na)TiO 3 - x BaTiO 3 films exhibit enhanced piezoelectric properties due to domain switching over a wide composition range. These properties were observed over a significantly wider composition range than the morphotropic phase boundary (MPB), which typically has a limited composition range of 1-2%. The polarization axis was found to be along the in-plane direction for the tetragonal composition range x = 0.06-1.0, attributed to the tensile thermal strain from the substrate during cooling after the film formation. A "two-step increase" in remanent polarization against an applied maximum electric field was observed at the high-field region due to the domain switching, and a very high piezoelectric response (effective d 33 value, denoted as d 33,f ) over 220 pm/V was achieved for a wide composition range of x = 0.2-0.5 with high tetragonality, exceeding previously reported values for bulk ceramics. Moreover, a transverse piezoelectric coefficient, e 31,f , of 19 C/m 2 measured using a cantilever structure was obtained for a composition range of at least 10 atom % (for both x = 0.2 and 0.3). This value is the highest reported for Pb-free piezoelectric thin films and is comparable to the best data for Pb-based thin films. Reversible domain switching eliminates the need for conventional MPB compositions, allowing an improvement in the piezoelectric properties over a wider composition range. This strategy could provide a guideline for the development of environmentally acceptable lead-free piezoelectric films with composition-insensitive piezoelectric performance to replace Pb-based materials with MPB composition, such as PZT.

Recent progress in two-dimensional ferroelectrics greatly expands the versatility and tunability in van der Waals heterostructure based electronics. However, the switching endurance issue that widely plagues conventional ferroelectrics in practical applications is hitherto unexplored for van der Waals layered ferroelectrics. Herein, we report the observation of unusual polarization fatigue behaviors in van der Waals layered CuInP 2 S 6 , which also possesses finite ionic conductivity at room temperature. The strong intertwinement of the short-range polarization switching and long-range ionic movement in conjunction with the van der Waals layered structure gives rise to unique morphological and polarization evolutions under repetitive electric cycles. With the help of concerted chemical, structural, lattice vibrational and dielectric analyses, we unravel the critical role of the synergy of ionic migration and surface oxidation on the anomalous polarization enhancement and the eventual polarization degradation. This work provides a general insight into the polarization fatigue characteristics in ionically-active van der Waals ferroelectrics and delivers potential solutions for the realization of fatigue-free capacitors., (© 2023. The Author(s).)

Background: This study aimed to investigate the association between proteinuria and long-term prognosis in patients with coronary artery disease., Methods: This was a single-center observational study. A total of 1351 patients were identified who underwent percutaneous coronary intervention, and whose urine data were available. Patients were divided into two groups according to the presence (n = 245) or absence (n = 1106) of proteinuria. All-cause and cardiovascular deaths were primarily evaluated., Results: The prevalence rates of hypertension and diabetes were significantly higher, and the baseline estimated glomerular filtration rate (eGFR) was lower in patients with proteinuria than in those without proteinuria. During the median follow-up of 4.1 years (interquartile range, 1.7-6.8 years), the occurrences of all-cause and cardiovascular deaths were significantly higher in patients with proteinuria. Multivariable Cox regression analysis indicated that the presence of proteinuria was a significant predictor of cardiovascular death as well as age, BMI, reduced eGFR, and left ventricular ejection fraction. When stratified into four groups based on eGFR category (eGFR <60 or ≥60 ml/min/1.73 m2) and absence or presence of proteinuria, the incidence rates of all-cause and cardiovascular deaths were highest in patients with proteinuria and eGFR less than 60 ml/min/1.73 m2. Furthermore, the incidence rates of all-cause and cardiovascular deaths were significantly higher in patients with proteinuria among both diabetic and nondiabetic patients., Conclusion: Proteinuria is associated with the long-term prognosis, and all-cause and cardiovascular deaths in patients with coronary artery disease, regardless of eGFR and the presence or absence of diabetes mellitus., (Copyright © 2023 Italian Federation of Cardiology - I.F.C. All rights reserved.)

Aim: The relationship between carotid artery ultrasound findings and clinical outcomes in patients who undergo percutaneous coronary intervention (PCI) has not been completely elucidated., Methods: This single-center retrospective study investigated 691 patients who underwent PCI and carotid ultrasound testing. Maximum carotid intima-media thickness (CIMT) was defined as the greatest CIMT at the maximally thick point among the common carotid artery, carotid bulb, and internal carotid artery. A carotid plaque was defined as vessel wall thickening with a CIMT ≥ 1.5 mm. The characteristics of carotid plaque (heterogeneity, calcification, or irregular/ulcerated surface) were evaluated visually. Patients were divided into those with and without heterogeneous carotid plaque (maximum CIMT ≥ 1.5 mm and heterogeneous texture). The endpoint was the incidence of a major adverse cardiovascular event (MACE) defined as a composite of cardiovascular (CV) death, myocardial infarction, and ischemic stroke., Results: Among 691 patients, 309 were categorized as having a heterogeneous plaque. Patients with heterogeneous plaques were at a higher risk of MACE than those without (p=0.002). A heterogeneous plaque was independently associated with MACE after adjusting for covariates (hazard ratio [HR], 1.71; 95% confidence interval [CI], 1.01-2.90; p=0.046). Calcified or irregular/ulcerated plaques were correlated with a higher incidence of MACE, but both were not independently associated with MACE (HR, 1.35; 95% CI, 0.69-2.64, p=0.38 and HR, 0.98; 95% CI, 0.57-1.69; p=0.95, respectively)., Conclusion: The presence of a heterogeneous carotid plaque in patients who underwent PCI predicted future CV events. These patients may require more aggressive medical therapy and careful follow-up.

Purpose: This study aimed to evaluate the correlation and diagnostic agreement between diastolic pressure ratio (dPR) and fractional flow reserve (FFR) in a Japanese real-world setting., Design: Prospective multicenter observational study., Methods: This study included 100 patients with intermediate coronary artery stenosis at 4 Japanese hospitals. For these lesions, FFR and dPR were measured using a guidewire with a sensor and a monitor to measure intravascular pressure. The correlation and diagnostic agreement between FFR and dPR were assessed. When both FFR and dPR were negative or positive, the results were considered to be concordant. When one was positive and the other was negative, the result was regarded as discordant (positive discordance, FFR > 0.80 and dPR ≤ 0.89; negative discordance, FFR ≤ 0.80 and dPR > 0.89)., Results: Overall, the FFR and dPR were well-correlated (R = 0.841). FFR and dPR were concordant in 89% of cases (concordant normal, 43%; concordant abnormal, 46%) and discordant in 11% (positive discordance, 7%; negative discordance, 4%). No significant difference was observed in the rate of concordant results between patients with and without diabetes mellitus. The diagnostic concordance rate was significantly different among the 3 coronary arteries (right coronary artery, 93.3%; left anterior descending artery, 93.2%; and left circumflex artery, 58.3%; P = .001). Additionally, the rate of concordant results tended to be higher when using intravenous administration of adenosine than when using intracoronary bolus injection of nicorandil (adenosine, 95.1%; nicorandil, 84.7%; P = .103)., Conclusion: We found that dPR was highly correlated with FFR, and diagnostic discordance was observed in 11% of the lesions. Several factors, including lesion location and medication for hyperemia, may cause the diagnostic discordance between dPR and FFR., Competing Interests: The authors have no conflicts of interest to disclose. Dr. Hideki Ishii received lecture fees from Astellas Pharma, AstraZeneca, Bayer Pharmaceutical Co.Ltd., Boehringer Ingelheim Japan, Bristol Myers Squibb, Daiichi-Sankyo, Mochida Pharma, Pfizer Japan Inc., and Tanabe Mitsubishi. Dr. Toyoaki Murohara received an unrestricted research grant for Department of Cardiology, Nagoya University Graduate School of Medicine from Astellas Pharma Inc., Daiichi-Sankyo Co., Ltd., Dainippon Sumitomo Pharma Co., Ltd., Kowa Co., Ltd., MSD K. K., Mitsubishi Tanabe Pharma Co., Nippon Boehringer Ingelheim Co., Ltd., Novartis Pharma K. K., Otsuka Pharma Ltd., Pfizer Japan Inc., Sanofi-aventis K. K., Takeda Pharmaceutical Co., Ltd., and Teijin Pharma Ltd..Dr. Masahiko Ando received research grant from Kyowa Kirin Co. Ltd. None of the remaining authors none have declared any conflict of interest., (Copyright © 2022 the Author(s). Published by Wolters Kluwer Health, Inc.)

Epitaxial layers of ferroelectric orthorhombic HfO 2 are frequently investigated as model systems for industrially more relevant polycrystalline films. The recent success in stabilizing the orthorhombic phase in the solid-solution cerium oxide - hafnium oxide system allows detailed investigations of external influences during fabrication. This report analyzes the ferroelectric properties of two thin film capacitors, which were post-deposition annealed in N 2 and O 2 atmospheres to achieve the orthorhombic phase after room temperature deposition. The samples, which exhibit very similar constituent phase, appear identical in conventional polarization-field hysteresis measurements. However, a significant switching speed difference is observed in pristine devices. Continued field cycling reduces the difference. Deeper analysis of switching transients based on the Nucleation Limited Switching model suggests that the O 2 heat treatment atmosphere results in an altered oxygen vacancy profile, which is reverted during ferroelectric cycling., (© 2022. The Author(s).)

An automated experiment in multimodal imaging to probe structural, chemical, and functional behaviors in complex materials and elucidate the dominant physical mechanisms that control device function is developed and implemented. Here, the emergence of non-linear electromechanical responses in piezoresponse force microscopy (PFM) is explored. Non-linear responses in PFM can originate from multiple mechanisms, including intrinsic material responses often controlled by domain structure, surface topography that affects the mechanical phenomena at the tip-surface junction, and the presence of surface contaminants. Using an automated experiment to probe the origins of non-linear behavior in ferroelectric lead titanate (PTO) and ferroelectric Al 0.93 B 0.07 N films, it is found that PTO shows asymmetric nonlinear behavior across a/c domain walls and a broadened high nonlinear response region around c/c domain walls. In contrast, for Al 0.93 B 0.07 N, well-poled regions show high linear piezoelectric responses, when paired with low non-linear responses regions that are multidomain show low linear responses and high nonlinear responses. It is shown that formulating dissimilar exploration strategies in deep kernel learning as alternative hypotheses allows for establishing the preponderant physical mechanisms behind the non-linear behaviors, suggesting that automated experiments can potentially discern between competing physical mechanisms. This technique can also be extended to electron, probe, and chemical imaging., (© 2022 Wiley-VCH GmbH.)

Piezoresponse force microscopy (PFM) is widely used for characterization and exploration of the nanoscale properties of ferroelectrics. However, quantification of the PFM signal is challenging due to the convolution of various extrinsic and intrinsic contributions. Although quantification of the PFM amplitude signal has received considerable attention, quantification of the PFM phase signal has not been addressed. A properly calibrated PFM phase signal can provide valuable information on the sign of the local piezoelectric coefficient-an important and nontrivial issue for emerging ferroelectrics. In this work, two complementary methodologies to calibrate the PFM phase signal are discussed. The first approach is based on using a standard reference sample with well-known independently measured piezoelectric coefficients, while the second approach exploits the electrostatic sample-cantilever interactions to determine the parasitic phase offset. Application of these methodologies to studies of the piezoelectric behavior in ferroelectric HfO 2 -based thin-film capacitors reveals intriguing variations in the sign of the longitudinal piezoelectric coefficient, d 33,eff . It is shown that the piezoelectric properties of the HfO 2 -based capacitors are inherently sensitive to their thickness, electrodes, as well as deposition methods, and can exhibit wide variations including a d 33,eff sign change within a single device., (© 2022 The Authors. Advanced Materials published by Wiley-VCH GmbH.)

The functionality of ferroelastic domain walls in ferroelectric materials is explored in real-time via the in situ implementation of computer vision algorithms in scanning probe microscopy (SPM) experiment. The robust deep convolutional neural network (DCNN) is implemented based on a deep residual learning framework (Res) and holistically nested edge detection (Hed), and ensembled to minimize the out-of-distribution drift effects. The DCNN is implemented for real-time operations on SPM, converting the data stream into the semantically segmented image of domain walls and the corresponding uncertainty. Further the pre-defined experimental workflows perform piezoresponse spectroscopy measurement on thus discovered domain walls, and alternating high- and low-polarization dynamic (out-of-plane) ferroelastic domain walls in a PbTiO 3 (PTO) thin film and high polarization dynamic (out-of-plane) at short ferroelastic walls (compared with long ferroelastic walls) in a lead zirconate titanate (PZT) thin film is reported. This work establishes the framework for real-time DCNN analysis of data streams in scanning probe and other microscopies and highlights the role of out-of-distribution effects and strategies to ameliorate them in real time analytics., (© 2022 The Authors. Advanced Science published by Wiley-VCH GmbH.)

Ferroelectric thin films are important because of their great potential for use in various electric devices such as ferroelectric random-access memory. It was expected that Bi 2 SiO 5 , a Si-containing ferroelectric material, would show improved ferroelectricity by targeting a film with the (001)-orientation (polar-axis) on the substrate. Although there was a narrow process window for the deposition of the (010)/(001)-oriented Bi 2 SiO 5 thin film, it was successfully prepared on a (101)-oriented TiO 2 single substrate using the pulsed layer deposition technique. The optimum film deposition conditions and film thickness were found, and in this material, the volume fraction of the (001)-oriented domain reached about 70%. By controlling film orientation to the polar axis, the remanent polarization value of this film was 4.8 μC cm -2 , which is the highest value among reported Bi 2 SiO 5 ., (© 2022. The Author(s).)

Pressure-induced phase transitions in a monoclinically distorted LiNbO 3 -type CuNbO 3 with triangularly coordinated Cu and octahedrally coordinated Nb were experimentally and computationally investigated. Phase transitions into GdFeO 3 -type or NaIO 3 -type structures generally observed in LiNbO 3 -type compounds below 30 GPa were not detected in CuNbO 3 even at the maximum experimental pressure, 32.4 GPa. Our density functional theory calculations revealed that the phase transition is suppressed by the preference for the CuO 3 triangular coordination environment, which reduces the total internal energy. This study clarifies that the change in the coordination environment of given ions can affect the pressure-induced phase transition.

Objective The relationship between cardiovascular disease and the serum polyunsaturated fatty acid parameters has been reported. The aim of the present study was to investigate the association between the eicosapentaenoic acid and arachidonic acid (EPA/AA) ratio and long-term cardiovascular events in patients with coronary artery disease. Methods We identified a total of 831 patients who underwent percutaneous coronary intervention and whose EPA/AA ratio was available. The patients were divided into two groups according to their serum EPA/AA ratio (median, 0.29; interquartile range 0.19-0.47): those in the lower quartile of EPA/AA ratios (Low EPA/AA group; n=231) and all other subjects (High EPA/AA group; n=600). The primary endpoints included a composite of cardiovascular death, myocardial infarction, and ischemic stroke. Results Patients in the Low EPA/AA group were significantly younger (66.0±12.6 years vs. 69.9±9.3 years, p<0.001), current smokers (33.3% vs. 22.7%, p=0.002), and had a history of myocardial infarction (20.3% vs. 12.3%, p=0.003). During the follow-up (median, 1,206 days; interquartile range, 654-1,910 days), the occurrence of the primary endpoint was significantly higher in the Low EPA/AA group than in the High EPA/AA group. Of note, the rate of cardiovascular death was significantly higher in the Low EPA/AA group, and the rates of myocardial infarction and stroke tended to be higher. Conclusion A low EPA/AA ratio was associated with long-term adverse cardiovascular events in Japanese patients with coronary artery disease.