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Sodium tantalate powder was synthesized and doped with suitable anions using a low-temperature hydrothermal process. The prepared samples were investigated for photocatalytic and electrochemical behavior using various characterization techniques. The crystal structure, stretching frequencies, and surface morphology were studied using X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM), respectively. The electrochemical performances of the samples were studied by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) analysis. Kinetics of hydrogen evolution (HER) and oxygen evolution (OER) reactions in a basic electrolyte were also investigated. From the above characterization techniques, it has been revealed that NaTaO 3 (or, NT), c-NaTaO 3 (or, cNT), and s-NaTaO 3 (or, sNT) have a cubic crystal structure in the perovskite phase and possess direct band gaps of energies 3.9 eV, 3.8 eV, and 3.7 eV, respectively. The average crystallite size of NT, cNT, and sNT is calculated as 15 nm, 12 nm, and 20 nm, respectively. sNT has higher capacitive properties than NT and cNT, but it cannot be considered a typical supercapacitor electrode material. However, all the samples have shown optimal performance in hydrogen and oxygen evolution processes.

The three dimensional (3D) Dirac semimetal is a new quantum state of matter that has attracted much attention recently in physics and material science. Here, we report on the growth of large plate-like single crystals of Cd 3 As 2 in two major orientations by a self-selecting vapor growth (SSVG) method and the optimum growth conditions have been experimentally determined. The crystalline imperfections and electrical properties of the crystals were examined with transmission electron microscopy (TEM), scanning tunneling microscopy (STM) and transport property measurements. This SSVG method makes it possible to control the as-grown crystal compositions with excess Cd or As leading to mobilities near 5–10 5 cm 2 V −1 s −1 . Zn-doping can effectively reduce the carrier density to reach the maximum residual resistivity ratio (RRR ρ 300K /ρ 5K ) of 7.6. A vacuum-cleaved single crystal has been investigated using angle-resolved photoemission spectroscopy (ARPES) to reveal a single Dirac cone near the center of the surface Brillouin zone with a binding energy of approximately 200 meV.

3 d -atom intercalated transition metal dichalcogenides (TMDs) exhibit complex magnetic and electronic states due to the interplay between localized and itinerant electrons. Here, we study the electronic structures of Cr 1/3 NbS 2 and Mn 1/3 NbS 2 using angle-resolved photoemission spectroscopy and first-principles calculations. The bands near the Fermi energy ( E F ), primarily derived from NbS 2 , are significantly modified by interlayer hybridization with 3 d orbitals. Governed by Hund’s rule coupling, the chemical potential, density of states (DOS), and correlation strength near E F exhibit anomalous changes. In Cr 1/3 NbS 2 , with half-filled e g orbitals, spin-up Cr 3 d -Nb 4 d hybridization produces a V -shaped DOS at E F . In both compounds, spin-down 3 d states hybridize with Nb 4 d orbitals near 1 eV, leading to downward shifts of the Nb states and strong spin polarization. These findings highlight the critical role of Hund’s coupling and orbital hybridization in shaping the low-energy physics of intercalated TMDs. 3 d -atom intercalated transition metal dichalcogenides present complex behaviour due to the interplay between localized and itinerant electrons. Here, the authors investigate Cr 1/3 NbS 2 and Mn 1/3 NbS 2 , revealing that Hund’s coupling and orbital hybridization significantly alter electronic structures, inducing strong spin polarization and anomalous changes in the density of states at the Fermi level.

The study reports the influence of rare-earth ion doping on the structural, magnetic, and magnetocaloric properties of ferrimagnetic Gd3−xRExFe5O12 (RE = Y, Nd, Sm, and Dy, x = 0.0, 0.25, 0.50, and 0.75) garnet compound prepared via facile autocombustion method followed by annealing in air. X-Ray diffraction (XRD) data analysis confirmed the presence of a single-phase garnet. The compound’s lattice parameters and cell volume varied according to differences in ionic radii of the doped rare-earth ions. The RE3+ substitution changed the site-to-site bond lengths and bond angles, affecting the magnetic interaction between site ions. Magnetization measurements for all RE3+-doped samples demonstrated paramagnetic behavior at room temperature and soft-ferrimagnetic behavior at 5 K. The isothermal magnetic entropy changes (−ΔSM) were derived from the magnetic isotherm curves, M vs. T, in a field up to 3 T in the Gd3−xRExFe5O12 sample. The maximum magnetic entropy change (−∆SMmax) increased with Dy3+ and Sm3+substitution and decreased for Nd3+ and Y3+ substitution with x content. The Dy3+-doped Gd2.25Dy0.75Fe5O12 sample showed −∆SMmax~2.03 Jkg−1K−1, which is ~7% higher than that of Gd3Fe5O12 (1.91 Jkg−1K−1). A first-principal density function theory (DFT) technique was used to shed light on observed properties. The study shows that the magnetic moments of the doped rare-earths ions play a vital role in tuning the magnetocaloric properties of the garnet compound.

The present study focuses on investigating the magnetic properties and the critical particle size for developing sizable spontaneous magnetic moment of bare Au nanoparticles. Seven sets of bare Au nanoparticle assemblies, with diameters from 3.5 to 17.5 nm, were fabricated with the gas condensation method. Line profiles of the X-ray diffraction peaks were used to determine the mean particle diameters and size distributions of the nanoparticle assemblies. The magnetization curves M(Ha) reveal Langevin field profiles. Magnetic hysteresis was clearly revealed in the low field regime even at 300 K. Contributions to the magnetization from different size particles in the nanoparticle assemblies were considered when analyzing the M(Ha) curves. The results show that the maximum particle moment will appear in 2.4 nm Au particles. A similar result of the maximum saturation magnetization appearing in 2.3 nm Au particles is also concluded through analysis of the dependency of the saturation magnetization MP on particle size. The MP(d) curve departs significantly from the 1/d dependence, but can be described by a log-normal function. Magnetization can be barely detected for Au particles larger than 27 nm. Magnetic field induced Zeeman magnetization from the quantum confined Kubo gap opening appears in Au nanoparticles smaller than 9.5 nm in diameter.

The study reports the synthesis and characterization of the magnetic and magnetocaloric effects of metal-oxide (MO) modified La0.7Ca0.3MnO3 perovskites manganite. The powder composite samples, with a nominal composition of (1 − x)La0.7Ca0.3MnO3-xMO (Wt.% x = 0.0, 2.5, 5.0), were prepared using the facile autocombustion method, followed by an annealing process. The phase purity and structure were confirmed by X-ray diffraction. Temperature and field-dependent magnetization measurements and Arrott analysis revealed mixed first- and second-order phase transition (ferromagnetic to paramagnetic) in composite samples. The phase transition temperature shifted to lower temperatures with the addition of MO in the composite. A large magnetic entropy change (4.75 JKg−1K−1 at 1T and 8.77 JKg−1K−1 at 5T) was observed in the La0.7Ca0.3MnO3 (LCMO) sample and was suppressed, due to the presence of the MO phase in the composite samples. On the other hand, the addition of MO as a secondary phase in the LCMO samples enhanced their relative cooling power (RCP). The RCP of all composite samples increased with respect to the pristine LCMO, except for LCMO–5%NiO. The highest RCP value of 267 JKg−1 was observed in LCMO–5%CuO samples, which was 23.4% higher than the 213 JKg−1 observed for the pure LCMO at a magnetic field of 5T. The enhanced RCP of these composites makes them attractive for potential refrigeration applications.

De Winter pattern in anterior leads has been extensively described. However, there is only one case report of this pattern in inferior leads in English literature. Here, we describe a case of acute inferior wall myocardial infarction with thrombotic right coronary artery occlusion who presented with the classical De Winter sign in inferior leads.

A blood pressure response to physical stress depends on various factors such as gender, body mass index, and resting blood pressure. Results: Rise of systolic blood pressure (SBP) and diastolic blood pressure (DBP) was observed immediately after isometric exercise in normotensive and hypertensive subjects. A blood pressure response to physical stress depends on various factors such as gender, body mass, baseline blood pressure, diet, and physical activity. Isometric handgrip exercise test is performed to check blood pressure reactivity by static contraction of a small muscle mass with significant changed in blood pressure with relatively small increase in HR and the cardiac output by producing a pressure load on the heart.

Myocardial infarction (MI) is typically followed by numerous lethal complications. One such complication is left ventricular free wall rupture (LVFWR). We present the case of a middle-aged hypertensive patient who had a history of unstable angina for seven days. He presented to the emergency room with chest pain, dyspnea, and unstable vital parameters. Clinical signs, electrocardiography, and echocardiography raised the suspicion of left ventricular free wall rupture with ST-segment elevation inferior wall and lateral wall MI. As a result, the patient received aggressive resuscitative measures. Later, he underwent surgical repair for cardiac rupture via cardiopulmonary bypass. Finally, the patient was discharged from the hospital on the 10th postoperative day. The window period from the onset of cardiac wall rupture to patient admission to the operating room is crucial. This case report highlights that a high index of suspicion for left ventricle free wall rupture should be considered for a patient presenting with MI and cardiogenic shock. Timely diagnosis and quick surgical intervention can deter complications and save the patient.

The general picture established so far for the links between superconductivity and magnetic ordering in iron chalcogenide Fe 1+y (Te 1-x Se x ) is that the substitution of Se for Te directly drives the system from the antiferromagnetic end into the superconducting regime. Here, we report on the observation of a ferromagnetic component that developed together with the superconducting transition in Fe-excess Fe 1.12 Te 1-x Se x crystals using neutron and x-ray diffractions, resistivity, magnetic susceptibility and magnetization measurements. The superconducting transition is accompanied by a negative thermal expansion of the crystalline unit cell and an electronic charge redistribution, where a small portion of the electronic charge flows from around the Fe sites toward the Te/Se sites. First-principles calculations show consistent results, revealing that the excess Fe ions play a more significant role in affecting the magnetic property in the superconducting state than in the normal state and the occurrence of an electronic charge redistribution through the superconducting transition.