Gradual Phase Research Articles

Repercussions of the Continuous Instability for the Quality of Education in the State of Libya: An Investigational Study within the Faculty of Education, University of Benghazi (UoB)

Many confirmed negative signs and facts point to the general deterioration of the quality of Libya’s entire education system, with serious consequences for the future of the state of Libya. This deterioration is due to countless factors, such as ongoing political and militant conflicts, semi-paralyzed educational administrations, a lack of continuing professional development (CPD), and insufficient awareness within the Ministry of Education (MoE) of the state of the education system. Other contributing factors are the inefficient educational legislations from the parliament and the poor desire of policy makers to empower profound research, teamwork, reform ideas, or any suggested transformational strategies. Furthermore, the Centralized Management System (CMS) has detrimental effects, along with official reports on corruption issues in the MoE. Parallel to these causes, other circumstances impact the quality of the input and output of the Libyan education system (LES), such as the prevailing culture, beliefs, and attitudes on how education should be, whose most significant features are memorization and indoctrination. Such challenges have produced unqualified leadership and a huge number of decision makers who have harmed the LES instead of supporting it. Moreover, as a result of the COVID-19 pandemic and various suspensions (strikes/wars) of basic, secondary, and even vocational university education, several classes were postponed, canceled, or disrupted, which led to a great loss of knowledge among both teachers and learners. Correspondingly, Elabbar’s ([1], p. 121; [2], p. 19) studies have raised the warning indications to the highest level for the government, parliament, and all education authorities in the state of Libya, stating that the whole LES “may collapse very soon” if they do not adopt serious steps and fundamental measures “before it is too late.” Thus, this research study attempts to investigate such impacts on the quality of the education process and knowledge management (QEPKM) among students, teaching assistants, lecturers, and administrators at the Faculty of Education, University of Benghazi (UoB), with a special focus on the English Department. To closely classify the scale of impacts on the LES, this study uses four qualitative tools to collect and analyze data gathered from a wide range of participants: official documents, authentic academic reports, and experimental face-to-face interviews. The study recommends adding bridge programs for present and new students at the Faculty of Education, besides returning to the annual system (for at least 8 years) instead of the existing semester system, in addition to endorsing Elabbar's [2] proposed seven years of connected gradual reform phases for the reform strategy of the entire LES; otherwise, if all leading authorities do not seriously act toward reform, the whole education system in Libya will face major failings.

Examining solid-state sintering of AlCoCrFeNi multi-principal element alloy by molecular simulations

With the emergence of solid-state sintering techniques for metal additive manufacturing of multicomponent alloys, understanding the fundamental sintering mechanisms is vital for effective process control. Here, we employ molecular dynamics simulations to investigate the mechanisms involved during solid-state sintering of AlCoCrFeNi multi-principal element alloy. Our results reveal that the cross migration of atoms between the surface of powder particles promotes neck growth while minimizing the surface free energy. This phenomenon is mediated by a transition from BCC to amorphous phase resembling a pre-melt and assisting in the densification as a function of temperature. Stress–strain analysis on the alloy single crystal at room temperature suggests that permanent plastic deformation occurs with a gradual phase change to FCC predicting a tensile strength of ∼ 1547 MPa at the onset of yield and a peak stress of 2267 MPa.

A Simple Analytical Model for Oil Production from Partially Fractured Reservoirs to Estimate Size of Finite Fracture Networks

Summary Most oil reservoirs are partially fractured, characterized by finite fracture networks (FFNs) in a sea of isolated fractures. It is necessary to determine size and shape of each FFN explicitly for reservoir simulation. FFN size is correlated with fracture connectivity, which is a function of fracture density, length, and angular scatter. Oil production from FFNs exhibits a long-term dual-porosity behavior. The initial fast rate (Phase I) represents depletion of matrix within FFN, and the subsequent gradual decline phase represents radial flow from the matrix outside the FFN perimeter. Thus, FFN size can be calculated from the cumulative oil production from Phase I, taking into account the pore volume, oil compressibility, and pressure decline. It is not always possible to identify the dual-porosity behavior by visual inspection. A mathematical model is needed to estimate FFN size. For this purpose, a set of three fundamental equations are derived for production rate, cumulative production, and pressure as a function of time. The model is a modified and simplified version of material balance equations with easy analytical solution. It is designed for fractured reservoirs with layer-bound fractures. Production is single-phase black oil under depletion drive. The analytical model was tested on four vertical wells. The unknown parameters such as FFN size, size of well drainage area, and fracture aperture are adjusted until an optimum fit to actual production data is obtained. FFN elliptical shape is estimated from average fracture strike and strike standard deviation. The results are validated by FFN size, fracture length, and aperture measurements from borehole images. The results are approximate but sufficient for preliminary mapping of FFNs with location and size and other critical attributes including fracture drainage area, matrix block size, fracture aperture, and permeability in partially fractured reservoirs.

Effect of Zr4+ substitution on the phase evolution and microwave dielectric properties of (Cu1/3Nb2/3)0.25Ti0.75-xZrxO2 ceramics

The effect of Zr4+ substitution for Ti4+ on the phase evolution and microwave dielectric properties of (Cu1/3Nb2/3)0.25Ti0.75-xZrxO2 (0 = x ≤ 0.35) ceramics prepared via conventional solid-state method has been investigated. With the increase of Zr substitution, the ceramics exhibit a gradual phase transition from a tetragonal rutile phase to an orthorhombic srilankite phase, where the synthesis of the srilankite phase at atmospheric pressure and temperature below 1200 °C in this study is reported for the first time. The crystal structure is tetragonal rutile type for the unsubstituted composition, orthorhombic srilankite type for the compositions with x > 0.30, and the compositions in between is a two-phase region with a mixture of rutile and srilankite. The Zr substitution has a great influence on the microstructure of the ceramics. In particular, for compositions where x > 0.1, the grain boundaries are surrounded by elongated powdery particles. The microwave dielectric properties of the ceramics are closely related to the phase transition process, in which Q × f is significantly improved and τf decreases almost linearly with the increase of the content of srilankite phase. Optimum microwave dielectric properties with a permittivity of 35.1, a Q × f value of 7270 GHz, and a near-zero τf of 9.0 ppm/°C are obtained in the ceramics with x = 0.3 sintered at 1150 °C for 4 h, which provides a new option for microwave devices requiring medium-permittivity dielectric ceramics.

A free account or not? Its effect upon information yield in strategic interviews with suspects

AbstractAsking suspects for a free account (FA) at the start of an interview is considered good practice in a growing number of police organisations, whereas in others it still is not commonplace. This study explored whether interviews with or without such an invitation yielded more information from guilty suspects. Students in safety and security committed a mock crime and were then interviewed using a strategy of gradual disclosure of evidence, in the experimental condition preceded with an FA invitation (n = 20) and without such an invitation in the control condition (n = 17). On average, relatively little information was collected in the FA phase and far more in the subsequent gradual disclosure phase. However, the FA condition yielded seven confessions, four of which were given already in the FA phase. The No FA condition yielded only two confessions. Other differences in yield were not found. These findings indicate that an FA invitation could lead to some relevant and important information, such as a confession, being gathered already at an early stage of an interview, and that such an invitation does not hamper the gathering of further information later in the interview.

Did Changes to Adult Hearing Aid Pathways Due to COVID-19 Affect Patient Outcomes? A Service Evaluation.

The objective of this study was to determine whether changes to adult hearing aid provision during COVID-19 affected patient outcomes or service efficiency. A service evaluation compared three cohorts: patients who had hearing aid provision prior to the COVID-19 pandemic (the conventional pathway); patients who had hearing aid provision during the initial national lockdown (remote fittings); and patients who had hearing aid provision during the gradual reopening phase (a blended service with both face-to-face and remote service provision). Outcomes measured the effectiveness and efficiency of the service, using the Glasgow Hearing Aid Benefit/Difference Profiles (GHABP/DP) and number of follow-up appointments required. Results were assessed using descriptive statistics and error bars, separately for new and existing users. This study included 240 hearing aid users. Remote fittings adversely impacted the effectiveness of provision for new hearing aid users with a reduction in all GHABP domains. While new users' benefit was equally as good for blended and conventional service provision, blended provision was less efficient and required more follow-up visits. For existing hearing aid users, no differences were seen in GHADP outcomes of different pathways and remote fittings increased service efficiency. Remote hearing aid fittings are less effective for new users than hearing aids fitted using standard face-to-face service provision or service provision using a blended model of remote and face-to-face care. Current pathways using a blended model of care are less efficient but equally effective for new hearing aid users compared with provision prior to COVID-19 and result in equivalent patient outcomes in terms of benefit. https://doi.org/10.23641/asha.21067585.

A Beam-Scanning Printed Dipole Antenna Fed by a Rectangular Patch With Periodic Structures

In this letter, a beam-scanning printed dipole antenna fed by a rectangular patch with periodic structures is proposed. A simple rectangular patch embedded with rampart line structures is used as the novel feeding structure for the planar dipole. The embedded rampart line structures are used to reduce the size and radiation of the rectangular patch, which facilitates feeding. By exciting the coupled modes of the dipoles, continuous and gradual phase differences for the dipole arms can be achieved so as to achieve beam scanning. A double-layer reflector and director are used to enhanced the antenna gains. In the simulated results, the dipoles radiated a beam that scanned from −48° to 14° in the azimuth planes as frequency changed. The measured results show consistent scanning beams within the operating bands from 3.16 to 3.24 GHz. The measured gain ranged from 3.27 to 5.58 dBi within the corresponding bands. Furthermore, the proposed antenna had a high radiation efficiency close to 90%, as well as a compact size.

Imaging and Spectroscopic Observations of the Dynamic Processes in Limb Solar Flares

We investigate various dynamic processes including magnetic reconnection, chromospheric evaporation, and coronal rain draining in two limb solar flares through imaging and spectroscopic observations from the Interface Region Imaging Spectrograph (IRIS) and the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory. In the early phase of the flares, a bright and dense loop-top structure with a cusp-like shape can be seen in multiwavelength images, which is cospatial with the hard X-ray 25–50 keV emission. In particular, intermittent magnetic reconnection downflows are detected in the time–space maps of AIA 304 Å. The reconnection downflows are manifested as redshifts on one half of the loops and blueshifts on the other half in the IRIS Si iv 1393.76 Å line due to a projection effect. The Si iv profiles exhibit complex features (say, multipeak) with a relatively larger width at the loop-top region. During the impulsive phase, chromospheric evaporation is observed in both AIA images and the IRIS Fe xxi 1354.08 Å line. Upward motions can be seen from AIA 131 Å images. The Fe xxi line is significantly enhanced and shows a good Gaussian shape. In the gradual phase, warm rains are observed as downward moving plasmas in AIA 304 Å images. Both the Si iv and Fe xxi lines show a relatively symmetric shape with a larger width around the loop top. These results provide observational evidence for various dynamic processes involved in the energy release process of solar flares and are crucial to the understanding of this process.

Temperature and differential emission measure evolution of a limb flare on 13 January 2015

Context. Spatially unresolved observations show that the cooling phase in solar flares can be much longer than theoretical models predict. It has not yet been determined whether this is also the case for different subregions within the flare structure. Aims. We aim to investigate whether or not the cooling times, which are observed separately in coronal loops and the supra-arcade fan (SAF), are in accordance with the existing cooling models, and whether the temperature and emission measure of supra-arcade downflows (SADs) are different from their surroundings. Methods. We analysed the M5.6 limb flare on 13 January 2015 using SDO/AIA observations. We applied a differential emission measure (DEM) reconstruction code to derive spatially resolved temperature and emission measure maps, and used the output to investigate the thermal evolution of coronal loops, the SAF, and the SADs. Results. In the event of 13 January 2015, the observed cooling times of the loop arcade and the SAF are significantly longer than predicted by the Cargill model, even with suppressed plasma heat conduction. The observed SADs show different temperature characteristics, and in all cases a lower density than their surroundings. Conclusions. In the limb flare event studied here, continuous heating likely occurs in both loops and SAF during the gradual flare phase and leads to an extended cooling phase.

Moderate Radio Flux Density of Single and Group III Bursts from AR2887 Active Region on 26th October 2021

The radio flux density is one of the most important parameters for predicting solar activity, such as solar flares and Coronal Mass Ejections. Compared to other burst types, solar burst type III (SRBT III) occurs most frequently due to solar flare phenomena. In the meter and decimetre wavelength range, gyro synchrotrons dominate, as do localized disturbances in the plasma frequencies caused by SRBT III. In this paper, we examine the most recent solar event that took place on 26th October 2021 in this gradual phase of the 25th solar cycle and can be detected from our site. In order to compare our results to other regions of the electromagnetic spectrum, we also used the data from the Solar Monitor and Space Weather Live website, where the data from NOAA and SDO/AIA were made publicly available. A wavelength of 10.7 cm corresponds to 101 solar flux units. Approximately 4.7 nT of interplanetary magnetic field exists and 1.7 nT in the northward direction. In the past 6 hours and 24 hours, flares of class C2 and M1 have been detected due to active region AR2887 generated by a 'beta-gamma' magnetic field.

Characterization of the Lattice Transitions and Impurities in Manganese and Zinc Doped Ferrite Nanoparticles by Raman Spectroscopy and X-ray Diffraction (XRD)

Temperature-induced phase transitions and the presence of impurities to the spinel phase ferrite nanoparticles were comparatively assessed using the same annealed samples, by Raman spectroscopy (RS) and X-Ray Diffraction (XRD), in order to point out advantages and disadvantages of either method depending on the research issue at hand. RS revealed gradual phase transitions from predominantly magnetite-like below 250 °C with the possibility of tracking cation vacancies, over maghemite-like at 300–600 °C, hematite-dominated in the 700–1000 °C range, and back to a spinel phase at 1100 °C with a different arrangement of cations on A-sites than the starting sample. On the other hand, XRD on the same samples showed abrupt transition from the spinel structure to hematite between 600 and 700 °C, and back to spinel at 1100 °C, but this technique performed better at revealing other oxide phases present below the identification threshold of Raman spectroscopy. Magnetization measurements support the phase transitions assignments, showing no saturation magnetization for the samples annealed at 700–900 °C, while those annealed at 1000 and 1100 °C re-gained saturation magnetization up to 31.7 emu/g. Magnetite- and maghemite-like structures in the 100–300 °C range are more clearly distinguished by RS than XRD, due to their isostructural character (both have face-centered cubic symmetry). These analytical aspects have to be understood in order to achieve more efficient and comprehensive characterization of synthesized ferrite nanoparticles.

An investment toward non-lethal crop protection measures for a threatened species in New South Wales: the Flying-fox Netting Subsidy Program

ABSTRACT Flying-fox depredation of cultivated fruit in eastern Australia has been contentious since early settlement and was often addressed by shooting flying-foxes. However, shooting is ineffective as a crop protection measure and has serious animal welfare impacts. Exclusion netting is considered the most reliable and humane method of protecting commercial crops from flying-foxes and other animals. From 2011 to 2017, the New South Wales (NSW) Government implemented the Flying-fox Netting Subsidy Program to subsidise fruit growers’ costs of installing exclusion netting on orchards, accompanied by the gradual phase out of legal shooting of flying-foxes in NSW. The AUD$7.1 million scheme was designed to fund up to 50 percent of the cost of purchasing and installing exclusion netting, capped at AUD$20,000 per hectare. The subsidy program was initially funded for AUD$5 million and restricted to full-canopy exclusion netting for orchards situated in the Sydney Basin and Central Coast but later expanded to the remainder of NSW and also expanded to subsidise throw-over netting and upgrades of non-complaint netting, with an additional investment of AUD$2.1 million. As a result, subsidies achieved netting of 182 hectares of crops in the Sydney Basin and Central Coast and 503 hectares in the remainder of NSW. The number of shooting licences granted by the NSW Government in growing seasons following the subsidy program were substantially lower than previous growing seasons and flying-foxes were reported shot at a lower rate following the subsidy program compared to previous growing seasons. These patterns suggest fruit growers’ diminishing reliance on using shooting as a crop protection measure in the years leading up to the NSW Government phasing out legal shooting of flying-foxes in June 2021.

Localized anisotropic stress in the sodiation of antimony anode

Although electrode degradation and failure in secondary batteries are hypothesized to stem from the localized chemo-electro-mechanical stress buildup during the charge-discharge process, the exact mechanism of stress generation is poorly understood. We quantitively resolve the stress accumulation in the Sb thin film anode during its gradual phase transitions in the sodiation/desodiation process by combining real-time electro-mechanical and electrochemical measurements with structural information further confirmed by spectroscopic methodologies. In the Sb thin films with (012) planes nearly normal to the surface, ~63% of the total interfacial stress (43.1 N m−1) is accumulated within the first 1/6 of the sodiation process of Na0.5Sb formation with Na-ions inserted between (012) planes. Only a small stress of 4.3 N m−1 is observed in the second 1/6 of the sodiation process due to preferential amorphization and solid solution formation. The last 2/3 of the sodiation process, where NaSb is converted into Na3Sb, generates only 1/3 of total stress (21.2 N m−1) because of the limited in-plane expansion. We also demonstrate that creating buffering voids can greatly reduce stress accumulation, especially during the early stage of the sodiation. The chemo-electro-mechanical insights from this work could serve as quantitative guidelines for the design and optimization of long-lasting Sb anode.

The time course of adaptation to distorted speech.

When confronted with unfamiliar or novel forms of speech, listeners' word recognition performance is known to improve with exposure, but data are lacking on the fine-grained time course of adaptation. The current study aims to fill this gap by investigating the time course of adaptation to several different types of distorted speech. Keyword scores as a function of sentence position in a block of 30 sentences were measured in response to eight forms of distorted speech. Listeners recognised twice as many words in the final sentence compared to the initial sentence with around half of the gain appearing in the first three sentences, followed by gradual gains over the rest of the block. Rapid adaptation was apparent for most of the eight distortion types tested with differences mainly in the gradual phase. Adaptation to sine-wave speech improved if listeners had heard other types of distortion prior to exposure, but no similar facilitation occurred for the other types of distortion. Rapid adaptation is unlikely to be due to procedural learning since listeners had been familiarised with the task and sentence format through exposure to undistorted speech. The mechanisms that underlie rapid adaptation are currently unclear.

Multi-instrument STIX microflare study

Context. During its commissioning phase in 2020, the Spectrometer/Telescope for Imaging X-rays (STIX) on board the Solar Orbiter spacecraft observed 69 microflares. The two most significant events from this set (of GOES class B2 and B6) were observed on-disk from the spacecraft as well as from Earth and analysed in terms of the spatial, temporal, and spectral characteristics. Aims. We complement the observations from the STIX instrument with EUV imagery from SDO/AIA and GOES soft X-ray data by adding imaging and plasma diagnostics over different temperature ranges for a detailed microflare case study that is focussed on energy release and transport. Methods. We used data from the GOES for SXR plasma diagnostics and SDO/AIA for carrying out high-cadence EUV imaging and reconstruction of differential emission measure (DEM) maps of the thermal flare plasma. The reconstructed DEM profiles were used to study the temporal evolution of thermal flare plasma in the kernels and loops independently. We derived the time evolution of the flare plasma parameters (EM, T) and thermal energy from STIX, GOES, and AIA observations. In particular, we studied the STIX spectra to determine the nonthermal emission from accelerated electrons. Results. A spectral fitting of the STIX data shows clear nonthermal emission for both microflares studied here. For both events, the plasma temperature and EM derived from STIX and GOES as well as the reconstructed DEM maps differ in absolute values and timing, with AIA (which is sensitive to lower plasma temperatures) lagging behind. The deduced plasma parameters from either method roughly agree with the values in the literature for microflares as do the nonthermal fit parameters from STIX. This finding is corroborated by the Neupert effect exhibited between the time derivative of the GOES SXR emission and the STIX HXR profiles. For the B6 event, for which such an analysis was possible, the non-thermal energy deduced from STIX roughly coincides with the lower estimates of the thermal energy requirement deduced from the SXR and EUV emissions. Conclusions. The observed Neupert effects and impulsive and gradual phases indicate that both events covered in this study are consistent with the standard chromospheric evaporation flare scenario. For the B6 event on 7 June 2020, this interpretation is further supported by the temporal evolution seen in the DEM profiles of the flare ribbons and loops. For this event, we also find that accelerated electrons can roughly account for the required thermal energy. The 6 June 2020 event demonstrates that STIX can detect nonthermal emission for GOES class B2 events that is nonetheless smaller than the background rate level. We demonstrate for the first time how detailed multi-instrument studies of solar flares can be performed with STIX.

Temperature-dependent photoluminescence of Co-evaporated MAPbI3 ultrathin films

The hybrid organic–inorganic perovskite (PVK) thin films have attracted amounts of interest in the past decade due to the thickness-depended quantum confinement effects and tunable band gap as well as the demands of device miniaturization. Vacuum deposition is a promising method to realize precise control of film thickness and composition, low-temperature processing, the good compatibility with dry processing and compatible with the modern silicon-based semiconductor industry. Here, we report on the temperature-dependent photoluminescence properties of MAPbI3 ultrathin films with long-term stability and high quality fabricated by the co-evaporation. XPS, AFM and XRD results reveal that an excess MAI vapor environment plays a key role in sample preparation. PL is more sensitive than XPS to detect trace MAPbI3-like materials with strong luminescence properties. Temperature- dependent PL measurements show that the bandgap of MAPbI3 films red-shifted with the temperature decreasing in the range from 298 to 78 K, which is opposite to that of the traditional semiconductors and can be attributed to the interaction between the electron–phonon and the thermal expansion induced band gap renormalization. Gradual phase transition from tetragonal one to orthorhombic one is observed to start between 108 and 118 K, which is lower than the reported sudden phase transition temperature of 150 K for bulk MAPbI3 and suggests the important role of quantum confinement in ultrathin films. Our findings provide a way to fabricate PVK ultrathin films with long-term stability for novel light emitting devices.

First-order and gradual phase transitions of ethane confined in MCM-41.

The first-order phase transition of ethane confined in MCM-41, i.e., capillary condensation, has been measured using an isochoric cooling procedure by differential scanning calorimetry (DSC) under conditions ranging from 206 K and 1.1 bar up to the pore critical point (PCP). The PCP has also been determined using the three-line method developed earlier based on the vanishing heat of phase transition. As in the bulk phase, no first-order phase transition can occur above the critical point, which also implies that vapor can transform into liquid gradually by following a path around the critical point through the supercritical region. For the first time, the gradual phase transition is demonstrated with ethane in MCM-41, which is achieved through a multistep process with paths proceeding around the PCP without crossing the capillary-condensation curve. The occurrence of the gradual phase transition in nanopores, thus the confined supercriticality, is confirmed while our consistent DSC measurements are also well demonstrated.

In Situ Electrochemical Transformation toward Structure Optimized VEG@MXene Cathode for Enhanced Zinc-Ion Storage.

Vanadium-based derivatives, featuring affordable cost and high theoretical capacity, have gathered widespread interest in the context of aqueous zinc-ion batteries (ZIBs). However, the further application of vanadium-based materials is hindered by the limited electrical conductivity and cycling lifespan. Herein, 1D chain-like structure vanadyl ethylene glycolate (VEG, (VO(CH2 O)2 )), growing on the Ti3 C2 Tx MXene nanosheets, is synthesized via a one-step oil-bath heating process as cathode materials for ZIBs. Benefiting from the hybrid structure with high conductivity and abundant reactive sites, the VEG@MXene cathode exhibits a remarkable specific capacity (360.3 mAh g-1 at 0.5 A g-1 ), and impressive capacity retention (up to 85.2% after 3000 cycles at 10 A g-1 ). Mechanism analysis reveals a gradual phase transition from the original VEG on MXene to the stable Zn3 V2 O7 (OH)2 ·2H2 O nanoflakes accompanied by continuous zinc ion intercalation/deintercalation, offering more pathways for zinc ion transport. This work suggests that engineering conductivity-enhanced vanadium-based materials is a rational approach for developing promising cathode materials of ZIBs.

Radio frequency power controlled [formula omitted] crystal phase transition from monoclinic to cubic

Rare earth oxides such as Gadolinia (Gd2O3) are extensively explored for buried oxide (BOX) application as a replacement for silicon dioxide (SiO2) in silicon-on-insulator (SOI) substrates. Of all the proposed methods, molecular-beam-epitaxy-based techniques have shown perfectly single-crystalline growth of Gd2O3. We present a radio frequency (RF) magnetron sputter based low-cost technique to grow single-crystalline Gd2O3 on Si (111) substrate. We show a gradual phase transition of the Gd2O3 layer from monoclinic to cubic by engineering the Gd2O3 deposition rate–i.e., tuning the RF power. We present a comparison amongst three samples as follows: (a) monoclinic; (b) monoclinic+cubic; (c) cubic at three different RF powers keeping the rest of the process conditions such as chamber pressure, Argon flow rate, etc., fixed. Further, we present a detailed structural characterization of all the three samples using a high-resolution X-ray diffraction system. Using the ω−2θ and pole-figure measurements we show a highly textured monoclinic Gd2O3 layer formation with (-402) crystal orientation in experiment (a). In experiment (c) we show phase transition of Gd2O3 from monoclinic to cubic by tuning the RF power. Finally, with experiment (b), we demonstrate that the aforementioned phase transition is a gradual phenomenon by highlighting a coexistence of both the monoclinic and cubic phases at an intermediate RF power. To ensure the electrical characteristics of the grown dielectric we present a metal oxide semiconductor capacitor structure fabrication for the monoclinic and the cubic Gd2O3 layers and benchmark the interface trap density, and dielectric constant against state-of-the-art literature. We show an improvement in the interface trap density, and reduction in the hysteresis from monoclinic to cubic phase transition due to an improved epitaxial relation between cubic Gd2O3 and Si(111) substrate. Such low-cost methods of growing single-crystalline Gd2O3 layer has the potential to replace the SiO2 BOX layer, and significantly bring down the manufacturing cost of the existing SOI wafer technology.

Angle control of far-field scattering based on all dielectric transmissive geometric phase metasurface in near-infrared region

For a common metasurface with gradual phase, once the metasurface element structure is designed, we can only obtain a limited number of abnormal deflection angles based on the different arrangement characteristics of the metasurface element structure. In order to obtain continuously varying anomalous deflection angles, we propose addition and subtraction operations for coded metasurface sequences. In order to simplify the design process, we use geometric phase coding units to construct coded metasurface sequences. We can perform the addition and subtraction operations for two initial encoding metasurface sequences, and a new encoding sequence can be obtained. And a new corresponding scattering angle can be achieved. One do not need to redesign the size of the coding unit, and a continuous variation of deflection angles can be realized.