Structural, Magnetic and Mossbauer Spectral Study Of Gd2Fe16Ga0.5RM0.5 (RM = Ti, V, Zr, Nb, Mo, W), Gd2Fe17-xTix (x = 0- 1.5) and Gd2Fe16Ga1-xTix (x = 0 1) Intermetallic Compounds

Parmanent magnetic material finds indutrial application ranging from motors, generators to computers, space vehicles and biomedical industries. There is a constant drive to improve magnetic properties to meet the emerging industrial demands. In the present study, rare-earth -TM intermetallics of type R2Fe17 is investigated, with specific aims of improving Curie temperature and along with to understand the structural and magnetic properties of these compounds.Series of Gd2Fe17 type substituted intermetallic compounds were carefully synthesized via arc melting. Gd2Fe17-xTix (x = 0, 0.25, 0.5, 0.75, 1, 1.25, 1.5) and Gd2Fe16Ga1-xTix (x = 0, 0.25, 0.5, 0.75, 1) were explored to understand the effect of substitution atoms on the net magnetic properties along with Curie temperature of the compound. A series of refractory metal doped Gd2Fe16Ga0.5RM0.5 (RM = Ti, V, Zr, Nb, Mo, W) were also explored to understand the role of refractory element doping on the phase formation and its effect on magnetic properties.Series of experiements with x-ray diffraction, vibration sample magnetometer and Mossbauer analysis revealed that the Ti substitution for Fe in Gd2Fe17-xTix improves the magnetic properties (Tc = 559 K) as compared to Gd2Fe17. On the other hand Tc of Gd2Fe16Ga1-xTix compound decreased with Ti substitution. The Tc variation in these compounds is related to the magnetovolume and exchange-interaction between Fe-Fe atoms. The magnetization reducction in Gd2Fe17-xTix was attributed to dilution effect while that in Gd2Fe16Ga1-xTix was related to hybridization of 3d Fe band

Geometric frustration and competing interactions in selected chalcogenide spinels

Quantum materials often exhibit exotic ground states that are of fundamental interest with potentialapplication in next generation technologies. Particularly important emerging areas of interest areskyrmion lattices, quantum spin liquids, and spin spirals. These quantum phases of matter originatewith frustrated interactions, the interplay of spin and lattice degree of freedom, and quantumfluctuations. These properties are readily found in AB2X4spinel materials which are the focus ofthis presentation. In chalcogenide spinel compounds, the A-sites form a diamond lattice structurethat can exhibit frustration due to the competing nearest neighbor and next neasrest neighborexchange interactions. Moreover, the B sites form a pyrochlore lattice which is a prototypefor geometrical frustration. The interactions withing the pyrochlore sublattice can be tuned byintroducing an alternating ordered vacancy on the A-site or by the ordered substitution of twoinequivalent ions on the A-site. For example, in LiGaCr4S8the different size of the Li+andGa3+ions results in the formation of an alternating array of larger and smaller Cr4tetrahedra or abreathing pyrochlore lattice.To demonstrate the approach that will be used for the proposed studies of chalcogenide spinels,I will present the results of neutron diffraction, X-ray diffraction, magnetic susceptibility, and heatcapacity measurements of LiGaCr4S8. The neutron diffraction and synchrotron X-ray diffractiondata reveal negative thermal expansion (NTE) below 111(4) K. The magnetic susceptibilitydeviates from Curie-Weiss behavior with the onset of NTE. At low temperature a broad peak in themagnetic susceptibility at 10.3(3) K is accompanied by the return of normal thermal expansion.These results indicate strong magnetoelastic coupling in LiGaCr4S8

Psychosocial Support during COVID-19 Pandemic

Amid COVID-19 pandemic, the entire world is having to deal with the physical and mental health crisis along with the different psychosocial issues. Alarming number of deaths globally has made the people survive a strict lockdown, shutdown and prohibition period which accelerated adaptive and maladaptive human responses to the crisis. These maladaptive human responses are correlated with adverse physical and mental health issues. During the time of pandemic, primary symptomatic treatments along with the preventive measures psychosocial support is crucial to better deal with the global crisis. The most significantly recommended psychosocial support during COVID-19 includes; staying informed, focusing on self-care, connecting to others virtually, taking time for physical activities, making schedules and seeking for help if needed

Incommensurate Magnetic Order in the Z2\mathbb{Z}_2 Kagome Metal GdV6_6Sn6_6

We characterize the magnetic ground state of the topological kagome metal GdV$_6$Sn$_6$ via resonant X-ray diffraction. Previous magnetoentropic studies of GdV$_6$Sn$_6$ suggested the presence of a modulated magnetic order distinct from the ferromagnetism that is easily polarized by the application of a magnetic field. Diffraction data near the Gd-$L_2$ edge directly resolve a $c$-axis modulated spin structure order on the Gd sublattice with an incommensurate wave vector that evolves upon cooling toward a partial lock-in transition. While equal moment (spiral) and amplitude (sine) modulated spin states can not be unambiguously discerned from the scattering data, the overall phenomenology suggests an amplitude modulated state with moments predominantly oriented in the $ab$-plane. Comparisons to the ``double-flat" spiral state observed in Mn-based $R$Mn$_6$Sn$_6$ kagome compounds of the same structure type are discussed.Comment: 5 pages, 4 figure

Establishment of dry-chemistry-based reference intervals of routine liver function tests for the adult population of Gandaki Province, Nepal.

Every clinical laboratory should ideally establish its own population-specific reference intervals (RIs) to promote precision and evidence-based medicine. However, clinical laboratories in Nepal find it easier to follow external RIs than establish their own, leading to a lack of RIs specific to the local population. This study thus aimed to establish RIs of routine LFTs for the adult population of Gandaki Province, Nepal, and compare them with the current RIs used by our laboratory. We established the dry-chemistry-based reference intervals of 11 common LFT parameters for the adult population of Gandaki Province, Nepal using the direct priori-based method. The combined and sex-specific 95% double-sided RIs of total protein, albumin, globulin, A/G ratio, bilirubin, aspartate aminotransaminase (AST), alanine aminotransaminase (ALT), AST/ALT ratio, and alkaline phosphatase (ALP) were established using non-parametric percentile method. The new RIs were also compared with the currently used RIs that were adopted from the reagent kit inserts. The newly established RIs for each LFT were: Total proteins: 68.0-69.0g/L, albumin: 39.0-52.0g/L; globulin: 27.0-42.0g/L; A/G ratio: 1.1-1.8; total bilirubin: 5.13-25.65μmol/L (0.30-1.50mg/dl); unconjugated bilirubin: 1.71-17.10μmol/L (0.10-1.00mg/dl); conjugated bilirubin: 0.00-10.26 μmol/L (0.00-0.60mg/dl); AST: 20.0-43.2U/L; ALT: 11.0-53.0 U/L; AST/ALT ratio: 0.7-2.1; ALP: 42.0-135.4U/L. The RIs of albumin, globulin, A/G ratio, AST, ALT, and AST/ALT ratio differed significantly (p < 0.05) between males and females. Moreover, calculated out-of-range values showed that up to 4-40% of apparently healthy adults were classified as having abnormal test results based on current RIs. The newly established RIs fulfil the need for population and platform-specific RIs for the adult population of Gandaki Province of Nepal and bring more conformity and accuracy in interpreting the LFT results, diagnosis of hepatobiliary diseases, clinical decision-making, monitoring the success of therapy and future liver specific biomedical researches within the Gandaki Province of Nepal

Traversing the pyrochlore stability diagram; microwave-assisted synthesis and discovery of mixed B-site Ln2_2InSbO7_7 family

The lanthanide pyrochlore oxides Ln$_2$B$_2$O$_7$ are one of the most intensely studied classes of materials within condensed matter physics, firmly centered as one of the pillars of frustrated magnetism. The extensive chemical diversity of the pyrochlores, coupled with their innate geometric frustration, enables realization of a wide array of exotic and complex magnetic ground states. Thus, the discovery of new pyrochlore compositions has been a persistent theme that continues to drive the field in exciting directions. The recent focus on the mixed B-site pyrochlores offers a unique route towards tuning both local coordination chemistry and sterics, while maintaining a nominally pristine magnetic sublattice. Here, we present a broad overview of the pyrochlore stability field, integrating recent synthetic efforts in mixed B-site systems with the historically established Ln$_2$B$_2$O$_7$ families. In parallel, we present the discovery and synthesis of the entire Ln$_2$InSbO$_7$ family (Ln: La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) located near the boundary of the pyrochlore stability field using a rapid, hybrid mechanicochemical/microwave-assisted synthesis technique. Magnetic characterization on the entire class of compounds draws striking parallels to the stannate analogs, suggesting that these compounds may host a breadth of exotic magnetic ground states

Comparative study of machine learning based prediction of supercapacitance performance of activated carbon prepared from Bio-based Materials

The performance of electrochemical double-layer capacitors (EDLCs) is evaluated by the capacitance of activated carbon (AC) electrodes. The capacitance of AC electrodes is influenced by many factors such as precursor type, activation method, pore structure, surface chemistry and electrolytic properties. In this paper, we present a comparative study of machine learning based prediction of surface area, mesopore volume and total pore volume of activated carbon for energy storage applications. The ML models were trained on a dataset of synthetic data that were generated from the limited number of experimental data and which included the activation temperature, methylene blue number and iodine number of the activated carbon (AC). The best performing ML model was random forest model and XG boost model. The results of this study can be used to optimize the production of activated carbon and improve its performance in energy storage applications

Frustrated charge order and cooperative distortions in ScV6Sn6

Here we study the stability of charge order in the kagome metal ScV6Sn6. Synchrotron x-ray diffraction measurements reveal high-temperature, short-range charge correlations at the wave vectors along q=(1/3,1/3,1/2) whose inter-layer correlation lengths diverge upon cooling. At the charge order transition, this divergence is interrupted and long-range order freezes in along q=(1/3,1/3,1/3), as previously reported, while disorder enables the charge correlations to persist at the q=(1/3,1/3,1/2) wave vector down to the lowest temperatures measured. Both short-range and long-range charge correlations seemingly arise from the same instability and both are rapidly quenched upon the introduction of larger Y ions onto the Sc sites. Our results validate the theoretical prediction of the primary lattice instability at q=(1/3,1/3,1/2), and we present a heuristic picture for viewing the frustration of charge order in this compound

Strain-induced enhancement of the charge-density-wave in the kagome metal ScV6_6Sn6_6

The kagome geometry is an example of frustrated configuration in which rich physics takes place, including the emergence of superconductivity and charge density wave (CDW). Among the kagome metals, ScV$_6$Sn$_6$ hosts an unconventional CDW, with its electronic order showing a different periodicity than that of the phonon which generates it. In this material, a CDW-softened flat phonon band has a second-order collapse at the same time that the first order transition occurs. This phonon band originates from the out-of-plane vibrations of the Sc and Sn atoms, and it is at the base of the electron-phonon-coupling driven CDW phase of ScV$_6$Sn$_6$. Here, we use uniaxial strain to tune the frequency of the flat phonon band, tracking the strain evolution via time-resolved optical spectroscopy and first-principles calculations. Our findings emphasize the capability to induce an enhancement of the unconventional CDW properties in ScV$_6$Sn$_6$ kagome metal through control of strain.Comment: Main text + S

Advances in high-pressure laser floating zone growth: the Laser Optical Kristallmacher II

The optical floating zone crystal growth technique is a well-established method for obtaining large, high-purity single crystals. While the floating zone method has been constantly evolving for over six decades, the development of high-pressure (up to 1000 bar) growth systems has only recently been realized via the combination of laser-based heating sources with an all-metal chamber. While our inaugural high-pressure laser floating zone furnace design demonstrated the successful growth of new volatile and metastable phases, the furnace design faces several limitations with imaging quality, heating profile control, and chamber cooling power. Here, we present a second-generation design of the high-pressure laser floating zone furnace, "Laser Optical Kristallmacher II" (LOKII), and demonstrate that this redesign facilitates new advances in crystal growth by highlighting several exemplar materials: ${\alpha}$-Fe$_2$O$_3$, $\beta$-Ga$_2$O$_3$, and La$_2$CuO$_{4+{\delta}}$. Notably, for La$_2$CuO$_{4+{\delta}}$, we demonstrate the feasibility and long-term stability of traveling solvent floating zone growth under a record pressure of 700 bar.Comment: 9 pages, 6 figure