Observation of helimagnetism in the candidate ferroelectric CrI2_2

CrI$_{2}$ is a quasi-one dimensional (1D) van der Waals (vdW) system that exhibits helimagnetism that propagates along the ribbons. This was determined from neutron time-of-flight diffraction measurements. Below $T_N=17$ K, a screw-like helimagnetic order develops with an incommensurate wavevector of $\mathbf{q} \approx (0.2492,0,0)$ at 8 K. Using density functional theory (DFT)$+U$ calculations, the $J_{1}$-$J_{2}$ model was leveraged to describe the helimagnetism, where $J_{1} (> 0)$ and $J_2 (< 0)$ correspond, respectively, to a ferromagnetic nearest neighbor (NN) and antiferromagnetic next-nearest neighbor (NNN) intrachain interaction. The DFT$+U$ calculations predict that bulk CrI$_2$ in the orthorhombic $Cmc2_1$ crystal structure satisfies the $|J_2| > |J_1|/4$ condition, which favors formation of helimagnetic order.Comment: main pdf file includes supplemen

A software framework for data dimensionality reduction: application to chemical crystallography

Materials science research has witnessed an increasing use of data mining techniques in establishing process‐structure‐property relationships. Significant advances in high‐throughput experiments and computational capability have resulted in the generation of huge amounts of data. Various statistical methods are currently employed to reduce the noise, redundancy, and the dimensionality of the data to make analysis more tractable. Popular methods for reduction (like principal component analysis) assume a linear relationship between the input and output variables. Recent developments in non‐linear reduction (neural networks, self‐organizing maps), though successful, have computational issues associated with convergence and scalability. Another significant barrier to use dimensionality reduction techniques in materials science is the lack of ease of use owing to their complex mathematical formulations. This paper reviews various spectral‐based techniques that efficiently unravel linear and non‐linear structures in the data which can subsequently be used to tractably investigate process‐structure‐property relationships. In addition, we describe techniques (based on graph‐theoretic analysis) to estimate the optimal dimensionality of the low‐dimensional parametric representation. We show how these techniques can be packaged into a modular, computationally scalable software framework with a graphical user interface ‐ Scalable Extensible Toolkit for Dimensionality Reduction (SETDiR). This interface helps to separate out the mathematics and computational aspects from the materials science applications, thus significantly enhancing utility to the materials science community. The applicability of this framework in constructing reduced order models of complicated materials dataset is illustrated with an example dataset of apatites described in structural descriptor space. Cluster analysis of the low‐dimensional plots yielded interesting insights into the correlation between several structural descriptors like ionic radius and covalence with characteristic properties like apatite stability. This information is crucial as it can promote the use of apatite materials as a potential host system for immobilizing toxic elements

High Entropy Rare Earth Oxide (HERO) Environmental Barrier Coatings for Refractory Metal Alloys

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Ponovni opis, biologija, životni ciklus, ponašanje i ekotip Sphedanolestes minusculus Bergroth (Hemiptera: Reduviidae)

Sphedanolestes minusculus Bergroth lays pale yellow eggs in batches. Eggs are glued to each other and to the substratum with cementing material. The average number of eggs per female was 63.33 ± 21.77. The eggs hatch in 7.80 ± 0.41 days. The average developmental period from I instar to V instar was 48.43 ± 7.39days. The longevity of the male (80.16 ± 5.23) was shorter (96.77 ± 11.88) than that of the female. The preoviposition period was 12.55 ± 3.43 days and the male and female sex ratio was 1: 1.5. The innate capacity of natural increase (rc) was 0.061 with a gross reproduction rate (mx) of 91.671 females per female. Mean length of generation (Tc) was 76.310 days. Redescriptions of adult and descriptions of egg and nymphal instars are given with illustrations. Predatory and mating behaviour exhibited sequential events as in other reduviids. Prey-deprived predators took less time to approach, capture and pin the prey. Individuals of S. minusculus collected from three different ecological and geomorphological habitats viz., Olavakod tropical rainforest, Sunkankadai scrub jungle and Aralvaimozhi semiarid zone exhibited pronounced diversities in their oviposition pattern, hatchability, incubation and stadial periods, nymphal mortality, adult longevity and sex ratio. These diversities are considered a specially adapted biological function collectively called ecotypism.Sphedanolestes minusculus Bergroth polaže blijedo žuta jaja u gomilicama. Jaja su ljepljivom tvari slijepljena međusobno kao i za podlogu. Srednja vrijednost broja jaja po ženki je bila 63,33 ± 21,77. Ličinke su se izvalile u 7,80 ± 0,41 dana. Srednja vrijednost razvojnog perioda od I do V stadija bila je 48,43 ± 7.39 dana. Dužina života mužjaka (80,16 ± 5,23) bila je kraća (96,77 ± 11,88) nego ženki. Preovipozicija jaja je trajala 12,55 ± 3.43 dana a omjer između mužjaka i ženki je bio 1:1,5. Urođen, svojstven kapacitet prirodnog porasta (rc) je bio 0,061 s maksimalnim omjerom reprodukcije (mx) od 91,671 ženki. Prosječna dužina života jedne generacije (Tc) bila je 76, 310 dana. Ponovo su opisani odrasli, a na novo jaja i ličinački stadiji prikazani slikama. Složeno predatorsko ponašanje i ponašanje tijekom parenja slijedilo je pravilan tok kao kod drugih vrsta porodice Reduviidae. Ovi predatori su brzi u lovu i pridržavanju ulova. Jedinke Sphedanolestes minusculus su bile sakupljane u tri različita ekološka i geomorfološka staništa: Olavakod - tropska kišna šuma, Sunkankadai - guštara đungle i Aralvaimozhi - semiaridna zona. Opisane su različitosti u: njihovim ovipozicijskim uzorcima, izlijeganju jaja, vremenu inkubacije, trajanju razvojnih stadija, ličinačkoj smrtnosti, dužini života odraslih, te omjeru spolova. Te razlike u opisanim karakteristikama smatraju se posebno prilagođenim biološkim funkcijama koje zajednički nazivamo ekotip

Accelerated search for BaTiO3-based piezoelectrics with vertical morphotropic phase boundary using Bayesian learning

An outstanding challenge in the nascent field of materials informatics is to incorporate materials knowledge in a robust Bayesian approach to guide the discovery of new materials. Utilizing inputs from known phase diagrams, features or material descriptors that are known to affect the ferroelectric response, and Landau–Devonshire theory, we demonstrate our approach for BaTiO(3)-based piezoelectrics with the desired target of a vertical morphotropic phase boundary. We predict, synthesize, and characterize a solid solution, (Ba(0.5)Ca(0.5))TiO(3)-Ba(Ti(0.7)Zr(0.3))O(3), with piezoelectric properties that show better temperature reliability than other BaTiO(3)-based piezoelectrics in our initial training data

Thermochemical stability of high entropy rare earth oxide (HERO) coatings for refractory alloys

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Development and evaluation of introgression lines with yield enhancing genes of the Indian mega-variety of rice, MTU1010

MTU 1010 is an early maturing and high-yielding mega rice variety widely grown in an area of 3 Mha. It is characterised by limited grain number and panicle branching. To improve the grain number in MTU 1010, an IRRI breeding line, IR121055-2-10-5 was utilized as donor to transfer yield-enhancing genes Gn1a and OsSPL14 (associated with increased grain number and better panicle branching, respectively) into MTU1010 by Marker-Assisted Backcross Breeding (MABB). At each backcross generation, foreground selection was carried out with Gn1a and OsSPL14- specific molecular markers, whilst background selection was done with a set of SSR markers polymorphic between the IR121055-2-10-5 and MTU1010. With the use of a gene-specific marker, homozygous BC2 F2 plants carrying the yield-enhancing gene were identified and advanced through pedigree-method of selection till BC2 F6 and best performing ten lines were selected and evaluated in replicated station trials for yield contributing traits, where grain number and brancing per panicle exhibited high significant and positive correlation with single plant yield. Three promising lines namely RP6353-5-8-13-24, RP6353-26-13-39-5 and RP6353-32-12-8-16 with higher grain number and yield than MTU1010 were identified and nominated for evaluation in Initial Varietal Trial-Aerobic (IVT-Aerobic) of All India Crop Improvement Programme on Rice (AICRP), of which RP6353-26-13-39-5 (IET28674), was promoted for further testing