Growth Regime Research Articles

SINGLE CRYSTALS GROWTH OF Ag7+x(P1-xGex)S6 (x = 0.1; 0.25; 0.33) SOLID SOLUTIONS

Ternary silver argyrodites exhibit a wide range of properties and are classified as promising solid-state conductors, thermoelectrics, photovoltaic and nonlinear optical materials. This is ensured by the peculiarity of the crystal structure of argyrodites, which combines a rigid anionic and a disordered cationic sublattice. This work is devoted to the development of a technological regime for growing high-quality single-crystalline samples of Ag7+x(P1-xGex)S6 (x = 0.1; 0.25; 0.33) solid solutions by the method of directed crystallization from the melt. Polycrystalline alloys of Ag7+x(P1-xGex)S6 (x = 0.1; 0.25; 0.33) solid solution were obtained from previously synthesized ternary Ag7PS6 and Ag8GeS6. The synthesis was carried out by a single-stage and single-temperature method at a maximum temperature of 1010°C. The phase composition of the synthesized alloys was determined by the XRD method. Phase analysis of the obtained polycrystalline alloys did not reveal reflections of impurity phases. The results of thermal studies of Ag7+x(P1-xGex)S6 alloys were used to develop a technological regime for single crystals growth. Ag7+x(P1-xGex)S6 single crystal was grown from the melt by the directional crystallization method. As a result of the research, high-quality single crystals of Ag7+x(P1-xGex)S6 solid solutions (x = 0.1; 0.25; 0.33) were obtained. According to the results of X-ray diffraction, it was established that the solid solution of the composition Ag7.1(P0.9Ge0.1)S6 crystallizes in the primitive cubic cell of SG P213, and the solid solutions Ag7.25(P0.75Ge0.25)S6 and Ag7.33(P0.67Ge0.33)S6 crystallizes in a metastable at room temperature high-temperature modification with SG F-43m.
 Keywords: argyrodites; single crystals; directional crystallization; phase analysis.

Nucleation Window of Ga2O3 and In2O3 for Molecular Beam Epitaxy on (0001) Al2O3

The epitaxial growth of Ga2O3 and In2O3 on (0001)-oriented Al2O3 by plasma-assisted molecular beam epitaxy is investigated. The synthesis of both materials underlies similar growth kinetics, with the formation of volatile suboxides limiting their growth in the metal-rich regime. Quantitative analysis of β-Ga2O3 and c-In2O3 growth kinetics has been performed on appropriate buffer layers mimicking homoepitaxial growth conditions. In particular, we investigate the influence of the amount of supplied atomic oxygen on the growth kinetics of β-Ga2O3. Considering the heteroepitaxial growth on bare (0001) Al2O3, we found that the observed nucleation window is much more limited than the expected growth window derived from homoepitaxial growth conditions. For Ga2O3 this was studied in detail and the upper limit of the nucleation window was determined in terms of the gallium to oxygen ratio on the growth surface and the growth temperature. Outside the nucleation window, we report that three monolayers α-(Al0.75±0.04Ga0.25∓0.04)2O3 formed in the initial stage of growth passivate the surface with respect to further β-Ga2O3 nucleation. We attribute the formation of this layer to the intermixing of a Ga-rich adlayer and Al atoms from the substrate until the solubility limit in the α-phase is reached. The observation is accompanied by a specific RHEED pattern with satellite reflexes assigned to a surface reconstruction in the metal-rich growth regime.

“Data, data, data” – post-Brexit data governance and its relation to the UK’s economic model

ABSTRACT This paper studies the UK’s post-Brexit turn toward softening data protection standards. It uses this case to develop a perspective on data governance that is rooted in the growth model framework. With this approach, it illustrates how incentives to ease data-based value creation can be tied to certain macroeconomic conditions. The studied data protection reform serves as a crucial event at which links between macroeconomic conditions and policy action promise to become particularly visible. As the analysis shows, the UK government’s policy discourse and actions reflect various facets of the country’s data economy that have special weight in the UK’s growth model: the importance of data markets and advertising, the role of tech and data in attracting foreign investments, and the general importance of tech and data-intense service industries. The case study therefore points to important analytical dimensions that are relevant more generally for the study of evolving growth regimes.

The evolution of fast-growing coral reef fishes.

Individual growth is a fundamental life history trait1-4, yet its macroevolutionary trajectories have rarely been investigated for entire animal assemblages. Here we analyse the evolution of growth in a highly diverse vertebrate assemblage-coral reef fishes. We combine state-of-the-art extreme gradientboosted regression trees with phylogenetic comparative methods to detect the timing, number, location and magnitude of shifts in the adaptive regime of somatic growth. We also explored the evolution of the allometric relationship between body size and growth. Our results show that the evolution of fast growth trajectories in reef fishes has been considerably more common than the evolution of slow growth trajectories. Many reef fish lineages shifted towards faster growth and smaller body size evolutionary optima in the Eocene (56-33.9 million years ago), pointing to a major expansion of life history strategies in this Epoch. Of all lineages examined, the small-bodied, high-turnover cryptobenthic fishes shifted most towards extremely high growth optima, even after accounting for body size allometry. These results suggest that the high global temperatures of the Eocene5 and subsequent habitat reconfigurations6 might have been critical for the rise and retention of the highly productive, high-turnover fish faunas that characterize modern coral reef ecosystems.

Distinct growth regimes of α-synuclein amyloid elongation

Addition of amyloid seeds to aggregation-prone monomers allows for amyloid fiber growth (elongation) omitting slow nucleation. We here combine Thioflavin T fluorescence (probing formation of amyloids) and solution-state NMR spectroscopy (probing disappearance of monomers) to assess elongation kinetics of the amyloidogenic protein, α-synuclein, for which aggregation is linked to Parkinson’s disease. We found that both spectroscopic detection methods give similar kinetic results, which can be fitted by applying double exponential decay functions. When the origin of the two-phase behavior was analyzed by mathematical modeling, parallel paths as well as stop-and-go behavior were excluded as possible explanations. Instead, supported by previous theory, the experimental elongation data reveal distinct kinetic regimes that depend on instantaneous monomer concentration. At low monomer concentrations (toward end of experiments), amyloid growth is limited by conformational changes resulting in β-strand alignments. At the higher monomer concentrations (initial time points of experiments), growth occurs rapidly by incorporating monomers that have not successfully completed the conformational search. The presence of a fast disordered elongation regime at high monomer concentrations agrees with coarse-grained simulations and theory but has not been detected experimentally before. Our results may be related to the wide range of amyloid folds observed.

Can We Rationally Design and Operate Spatial Atomic Layer Deposition Systems for Steering the Growth Regime of Thin Films?

Fine control over the growth of materials is required to precisely tailor their properties. Spatial atomic layer deposition (SALD) is a thin-film deposition technique that has recently attracted attention because it allows producing thin films with a precise number of deposited layers, while being vacuum-free and much faster than conventional atomic layer deposition. SALD can be used to grow films in the atomic layer deposition or chemical vapor deposition regimes, depending on the extent of precursor intermixing. Precursor intermixing is strongly influenced by the SALD head design and operating conditions, both of which affect film growth in complex ways, making it difficult to predict the growth regime prior to depositions. Here, we used numerical simulation to systematically study how to rationally design and operate SALD systems for growing thin films in different growth regimes. We developed design maps and a predictive equation allowing us to predict the growth regime as a function of the design parameters and operation conditions. The predicted growth regimes match those observed in depositions performed for various conditions. The developed design maps and predictive equation empower researchers in designing, operating, and optimizing SALD systems, while offering a convenient way to screen deposition parameters, prior to experimentation.

On the occurrence of buoyancy-induced oscillatory growth instability in directional solidification of alloys

Recent solidification experiments identified an oscillatory growth instability during directional solidification of Ni-based superalloy CMSX4 under a given range of cooling rates. From a modeling perspective, the quantitative simulation of dendritic growth under convective conditions remains challenging, due to the multiple length scales involved. Using the dendritic needle network (DNN) model, coupled with an efficient Navier-Stokes solver, we reproduced the buoyancy-induced growth oscillations observed in CMSX4 directional solidification. These previous results have shown that, for a given alloy and temperature gradient, oscillations occur in a narrow range of cooling rates (or pulling velocity, V p ) and that the selected primary dendrite arm spacing (Λ) plays a crucial role in the activation of the flow leading to oscillations. Here, we show that the oscillatory behavior may be generalized to other binary alloys within an appropriate range of (V p ,Λ) by reproducing it for an Al-4at.%Cu alloy. We perform a mapping of oscillatory states as a function of V p and Λ, and identify the regions of occurrence of different behaviors (e.g., sustained or damped oscillations) and their effect on the oscillation characteristics. Our results suggest a minimum of V p for the occurrence of oscillations and confirm the correlation between the oscillation type (namely: damped, sustained, or noisy) with the ratio of average fluid velocity over V p . We describe the different observed growth regimes and highlight similarities and contrasts with our previous results for a CMSX4 alloy.

Scaling dynamics and universality of fission-gas-bubble growth in amorphous systems

ABSTRACT We present a generalised approach for describing the universal dynamics and statistical properties of fission gas bubble growth in amorphous systems, using as an example. We examine the scaling properties of both the growth and coalescence regimes of bubble growth, and find that the scaling exponents in these regimes are controlled by the fission rate and temperature. The nucleation regime is characterised by a growth exponent close to 1/2, while the coalescence regime is characterised by a growth exponent around 1/3. We show that the statistical distribution over bubble size is of a universal character. Analytical results are verified by numerical simulations and clarified with experimental data. This study provides insight into the kinetics of fission gas bubble growth in amorphous systems.

Partial identification for growth regimes: The case of Latin American countries

AbstractThis study introduces the partial identification of the structural vector autoregressive model to estimate the effect of income distribution on output. For this purpose, this study follows the Post‐Keynesian growth models and identifies the demand regimes in Latin American countries for the period 1960–2014. The main results reveal that Bolivia, Colombia, Honduras, and Panama have profit‐led regimes. In addition, Costa Rica, Nicaragua, Peru, and Uruguay have wage‐led regimes. The regimes of Brazil, Chile, Ecuador, and Mexico could not be determined.

Self-Patterning of Polyelectrolyte Multilayer Films: The Roles of PSS Molecular Weight, the Top Layer, and Post-Preparation Treatment

The self-patterning of thin films is relevant for both fundamental research and applications. We investigate polyelectrolyte multilayer films made from poly(diallyldimethylammonium) chloride and poly(styrene sulfonate) sodium salt (PDADMA/PSS). Various PSS with low molecular weight were used. First, the film thickness increases exponentially with the number of deposited PDADMA/PSS bilayers. The separation and height of the pillar-like domains increase significantly with each deposited PDADMA/PSS bilayer, as AFM images show. After the exponential growth regime, either a parabolic (and then a linear) or a linear growth regime follows, depending on the PSS molecular weight. The domain separation changes less and correlates with the vertical growth regimes. The domain separation varies between 70 and 750 nm and always exceeds the domain height. PSS-terminated films show the same domain distance in water and air. However, when PDADMA-terminated films are dried, the domain distance in air increases while the domain height decreases, causing a reduction in total area. In the air, the surface energy is greater than in water and a highly textured surface costs a lot of energy. We propose that the changed surface pattern is attributable to energy minimization. Furthermore, the domains are stable when exposed to 1 M NaCl solution but shrink enormously in 2 M NaCl, while their separation increases slightly. Under certain conditions, 50 nm broad filaments consisting of PDADMA/PSS complexes are observed. We suggest that these complexes diffuse between the domains and adjust their separation.

Agent-Based Model for Studying the Effects of Solid Stress and Nutrient Supply on Tumor Growth

An off-lattice agent-based model of tumor growth is presented, which describes a tumor as a network of proliferating cells, whose dynamics depend on the stress generated by intercellular bonds. A numerical method is introduced that ensures the smooth dynamics of the cell network and allows for relative numerical cheapness while reproducing the effects typical of more complex approaches such as the elongation of cells toward low-pressure regions and their tendency to maximize the contact area. Simulations of free tumor growth, restricted only by the stress generated within the tumor, demonstrate the influence of the tissue hydraulic conductivity and strength of cell–cell interactions on tumor shape and growth rate. Simulations of compact tumor growth within normal tissue show that strong interaction between tumor cells is a major factor limiting tumor growth. Moreover, the effects of normal tissue size and strength of normal cell interactions on tumor growth are ambiguous and depend on the value of tissue hydraulic conductivity. Simulations of tumor growth in normal tissue with the account of nutrients yield different growth regimes, including growth without saturation for at least several years with the formation of large necrotic cores in cases of low tissue hydraulic conductivity and sufficiently high nutrient supply, which qualitatively correlates with known clinical data.

Dynamics of Macroeconomic Uncertainty on Economic Growth in the Presence of Fiscal Consolidation in South Africa from 1994 to 2022

This paper investigates the effects of macroeconomic uncertainty on economic growth in the presence of fiscal consolidation in South Africa. Markov-switching dynamic regression (MSDR) and time-varying parameter vector autoregression (TVP-VAR) were performed using time series data from 1994 to 2022. Less attention has been given directly to the investigation of macroeconomic uncertainty in different regimes of economic growth in South Africa. Three states are found for economic growth, with mean growth rates of negative 6.29% and positive 3.90% and 1.47%, respectively. Macroeconomic uncertainty was found to have a negative impact of 6.72%, 4.38%, and 3.08% in states 1 to 3, respectively. Fiscal consolidation provided an accommodative policy, as it reduced the negative impact of macroeconomic uncertainty by 3.17%, 1.80%, and 0.92% in states 1 to 3, respectively. However, fiscal consolidation does not completely reduce the negative impact of macroeconomic uncertainty. The transition probabilities of economic growth moving and returning to the same states are 29.46%, 34.07%, and 58.02%, in each state, respectively. The time-varying impulse response functions showed that the shock of macroeconomic uncertainty harms economic growth. Nevertheless, the multiplier effect is not large; however, the economy operates below equilibrium and does not restore equilibrium after the effect of macroeconomic uncertainty. This reflects that it takes time for macroeconomic uncertainty to filter out of the South African economy. It is recommended that fiscal consolidation be considered as an accommodative fiscal policy to reduce macroeconomic uncertainty but not as a main policy for economic growth.

Moss-like Growth of Metal Electrodes: On the Role of Competing Faradaic Reactions and Fast Charging

Uncontrolled crystal growth during electroreduction of reactive metals in liquid electrolytes produces mossy metal deposits. Here, we use electroanalytical rotating disk electrode (RDE) studies to elucidate the origin of moss-like electrodeposition of metals. Competing Faradaic reactions on the electrode surface are shown to be the source of the phenomenon. A moss-like growth regime can be accessed by subtle shifts in electrolyte chemistry and deposition rate. For Zn─a metal that conventionally is not known to form moss-like electrodeposits─obvious moss-like patterns emerge at low-current densities in strongly alkaline electrolytes. Conversely, under conditions where the electroreduction rate is large relative to competing Faradaic reactions, moss-like Zn growth is eliminated. The same principle holds for Li metal deposition. On that basis, an empirical rule is proposed─an applied current density i that satisfies the relation 10 is < i < 0.8 ilim is required for achieving favorable metal electrodeposit morphology and fast charging in batteries.

Response of forest productivity to changes in growth and fire regime due to climate change

Climate change is having complex impacts on the boreal forest, modulating both tree growth limiting factors and fire regime. However, these aspects are usually projected independently when estimating climate change effect on the boreal forest. Using a combination of three different methods, our goal is to assess the combined impact of changes in growth and fire regime due to climate change on the timber supply at the transitions from closed to open boreal coniferous forests in Québec, Canada. To identify the areas that are likely to be the most sensitive to climate change, we projected climate-induced impacts on growth and fire activity at three different time periods: 2011–2040 RCP 8.5 for low growth change and minimum fire activity, 2071–2100 RCP 4.5 for moderate growth change and medium fire activity, and 2071–2100 RCP 8.5 for high growth change and maximum fire activity. Our study shows the importance of incorporating fire in strategic forest management planning especially in a context of climate change. Under the most extreme scenarios, the negative impact of fire activity on productive area and total volume mostly offsets the positive effects of climate change via improved tree growth.

Synchronization in Cycles of China and India During Recent Crises: A Markov Switching Analysis.

We study the impact of recent crisis episodes viz. the Great Recession of 2007-09, the Euro Area crisis of 2010-12 and the COVID-19 pandemic of 2020-21 on the Emerging Market Economies (EMEs) of China and India using data from January, 1986 till June, 2021. A Markov-switching (MS) analysis is applied to discern economy-specific cycles/regimes and common cycles/regimes in the growth rates of the economies. We apply the univariate MS Autoregressive (MS-AR) model to characterize country-specific negative growth, moderate growth and high growth regimes of China and India. We examine the extent of overlap of the identified regimes with the Great Recession, the Eurozone crisis, and the COVID-19 pandemic. Thereafter, we study the regimes depicting common phases in growth rates of China-India and China-India-US by using multivariate MS Vector Autoregressive (MS-VAR) models. The multivariate analysis shows the presence of common negative growth during the turbulent periods during the study period. These results can be explained by the existence of strong trade and financial linkages between the two EMEs and the Advanced economies. The pandemic triggered a recession in the Chinese, Indian and U.S. economies and its impact on growth is much worse than the Great Recession and the Eurozone crises.

The Political Economic Sources of Policy Non-design, Policy Accumulation, and Decay in Policy Capacity

This article problematizes the political economic drivers of policy (non-)design, instrument choice, and how prolonged non-design could trigger policy accumulation with serious implications for policy capacity. Focusing on the currency crisis-induced economic crisis in Turkey and relying on elite interviews and secondary resources, it argues that the design space, which is defined by the interactions between the credit-led growth model and the growth regime that prioritizes loose monetary and bank regulatory policies for higher economic growth rates, led to haphazard crisis response. Prolonged non-design in response to the crisis triggered policy accumulation and decay in systemic and organizational policy capacity.

Toward ultraclean correlated metal CaVO3

We report the synthesis and electronic properties of the correlated metal CaVO3, grown by hybrid molecular beam epitaxy. Films were grown on (100) LaAlO3 substrates at a temperature of 900 °C by supplying a flux of elemental Ca through a thermal effusion cell and metalorganic precursor, vanadium oxitriisopropoxide, as a source of vanadium. The presence of a self-regulated growth regime was revealed by the appearance of a specific surface reconstruction detected by reflection high-energy electron diffraction. Films grown within the growth window were characterized by atomically flat surfaces. X-ray reciprocal space maps revealed that the films were coherently strained to the substrate and inherited its twinned microstructure. Despite the presence of twin walls, CaVO3 thin films, grown within the stoichiometric growth window, revealed very low electrical resistivities at low temperatures, with residual resistivity ratios exceeding 90, while films grown at either Ca- or V-excess show deteriorated transport properties, attributed to the presence of extrinsic defects arising from the non-stoichiometry present in these films.

‘The mystery of Dublin’: Corporate profit-shifting and housing crisis in twenty-first century Ireland

Ireland’s economy is currently characterized by two phenomena: a highly globalized growth regime predicated on multinational corporate profit-shifting, and a domestic economy (concentrated in the capital, Dublin) experiencing severe housing crisis. This paper links these two phenomena together, and argues that they be considered as evidence of the emergence of a new accumulation regime, in which a specific mode of integration within the global economy both favours the emergence of, and embeds, particular patterns of domestic rent exploitation. To demonstrate this the paper combines a new synthesis of French régulation theory, as modified to account for transnational dynamics, with an updated reading of Gramsci’s analysis of (pre-Fordist) rent exploitation, applying this framework to redefine Ireland’s growth model as an emerging transnational accumulation regime of rentier character.

Comparative Green Advantage: Growth Regimes and Public Investment in Renewable Energy R&amp;D

AbstractMany consider research and development (R&amp;D) a crucial pillar of decarbonization, yet few have investigated what actually drives investment. What drives public investment in renewable energy R&amp;D in wealthy democracies? Using OECD data, this research note tests a number of hypotheses from the literature and finds that public investment in renewable energy R&amp;D is most closely associated with growth regimes and their related characteristics. Furthermore, the ‘most invested’ are dynamic services export‐led growth regimes who are deindustrializing and moving towards knowledge‐based sectors like information and communications technology and finance. In short, economies investing the most in renewable energy R&amp;D have the least structurally carbon‐intensive growth regime. As international economic integration locks many countries into specific path‐dependent roles, these findings suggest that there is a comparative advantage to the green transition. It concludes with a discussion of the asymmetric green capacities between core and periphery countries in the European Union.

Phase separation kinetics of binary mixture in the influence of bond disorder: sensitivity to quench temperature

ABSTRACT Morphologies in phase-separating systems can significantly influence final material properties. We present extensive Monte Carlo simulation results on segregation kinetics of critical binary mixture (-Ising system) with a fraction of bond disorder introduced regularly. The effect of various quench temperatures is studied on growth kinetics and scaling properties of evolved morphologies. The morphology changes from their usual bicontinuous isotropic patterns at zero disorder to short strips and lamellar patterns (anisotropy) with the increasing disorder at shallow quench depth. The domain evolution at lower disorder remains at a transient growth regime for deep quench; however, the lamellar pattern is observed at high disorder for the same quench depth. The scaling behavior changes significantly with quench depths at the higher fraction of disorder. Though, a tiny deviation is observed at lower disorder fractions for shallow quench depths. The length scale freezes () to finite size at the higher disorder asymptotically.