Structure and Lattice Dynamics of R $$_2$$ 2 Sn $$_2$$ 2 O $$_7$$ 7 and R $$_2$$ 2 Zr $$_2$$ 2 O $$_7$$ 7 (R = La–Lu) Crystals: Ab Initio Calculation

Journal of Superconductivity and Novel Magnetism - Crystal structure and phonon spectrum of rare-earth stannates R $$_2$$ Sn $$_2$$ O $$_7$$ and zirconates R $$_2$$ Zr $$_2$$ O $$_7$$ (R =...     

Electronic and Magnetic Properties of the BaTiO $$_{3}$$ 3 /LaMnO $$_{3}$$ 3 Interface: a DFT Study

Journal of Superconductivity and Novel Magnetism - The electronic and magnetic properties of the BaTiO $$_{3}$$ /LaMnO $$_{3}$$ interface were investigated by means of ab initio calculations within...     

Ab initio Insight of the Electronic,Structural, Mechanical and Optical Properties of X $$_3$$ 3 P $$_2$$ 2 (X= Mg,Ca) from GGA and Hybrid Functional (HSE06)

Journal of Superconductivity and Novel Magnetism - In this paper, the structural, mechanical and optoelectronic properties of X $$_3$$ P $$_2$$ (X= Mg, Ca) have been investigated by using the...     

Physical Properties of Antiferromagnetic Dirac Semimetal SrMnSb $$_{2}$$

Journal of Superconductivity and Novel Magnetism - We have prepared high-quality nearly stoichiometric single crystal of Dirac semimetal SrMnSb $$_{2}$$ and systematically investigated the physical...     

X-Ray Diffraction Study of Correlated Electron System at Low Temperatures

By using an ultra-low temperature X-ray diffractometer, we studied low temperature phase transitions of several materials. These phase transitions are classified into a ferro quadrupole ordered phase, that is, Jahn–Teller distortion (TmVO, ZnCrO), an antiferro quadrupole ordered phase (CeB, PrPb), and a superconducrivity (MgB). We also investigated unknown phases, such as the low temperature phase in PrPtBi and the 4th phase in CeLaB. Our low temperature X-ray measurement gives rise to a fruitful information about the phase transition. Not only a whole profile of the reflection peaks, which can be analyzed by the Rietveld method, we also made the precise measurement of the temperature dependence of the integrated intensity of the reflection peak, the full width at half maximum, and the lattice spacing for some fixed reflections. The temperature dependence of the integrated intensity (I.I.) can be expressed by the Debye–Waller expression. At low temperatures, the change of the phonon frequency can be obtained from the I.I. through the Debye–Waller factor. In MgB we observed the hardening of the phonon and the softening of phonon above and below the superconducting transition temperature, respsctively. This result suggests the relevant mechanisim of superconductivity in MgB is the electron–phonon interaction. From the precise measurement of the lattice constant, we found the negative thermal expansion at low temperatures in many correlated electron system. This negative thermal expansion can be explained by the Fermi liquid theory by Misawa.     

The Magnetic Properties of Different Proportions Cr-Doped Bifeo3 as Studied Using Heisenberg Model

Journal of Superconductivity and Novel Magnetism - With the Monte Carlo method, we simulate 3D alloys Heisenberg model of Cr-doped BiFeO $$_3$$ with various proportions Cr-doped. This model...     

Two-Band Eliashberg Theory in Doped MgB $_{2}$_{2}: Experimental Tc and Superconductive Gaps

The variation of the critical temperature and of the superconductive gaps as functions of doping (Al, C) in the diboride MgB has been studied in the framework of the two-band Eliashberg theory and traditional phonon coupling mechanism. We have solved the two-band Eliashberg equations using first-principle calculations or simple assumptions for the variation of the relevant physical quantities. We have found that the experimental curves can be exactly explained only if the Coulomb pseudopotential changes with x by tuning the Fermi level toward the σ band edge. We also found that a small amount of impurities changes the structural properties of the material, so we cannot treat the Mg and MgB systems as a contamination with Al or C of MgB, but as new materials. Finally, we compare the predictions of our theory with the available experimental data.     

Lead-strontium titanate glass ceramics: I – crystallization and microstructure

The crystallization behaviour of glasses in the system [(Pb Sr ) O·TiO₂]-[2SiO₂· B₂O₃]-[K₂O]-[BaO] (0.2 ≤ x ≤ 0.9) have been studied. Perovskite titanate was found to be the major phase in all the glass ceramic samples investigated. The actual composition of crystalline phases could not be confirmed on the basis of shift in the X-ray diffraction (XRD) peak positions because of similar effects due to solid solution formation and strain due to crystal clamping. Comparison of the observed intensities of various XRD peaks of the perovskite titanate phase with the calculated intensities for (Pb Sr )TiO₃ with same lead/strontium ratio confirmed the formation of lead strontium titanate solid solution. Microstructural characteristics of various glass ceramics are also discussed. The advantages of using K₂O and BaO as additives instead of only K₂O are also discussed.     

Study of Cuprate Superconductivity Using the Particle Number Conserving Bogoliubov-de Gennes Equations: ARPES and STS Images From Surface Plus Bulk Layers Model

Journal of Superconductivity and Novel Magnetism - We theoretically study the superconductivity in hole-doped cuprate superconductors by employing a model composed of surface and bulk CuO $$_2$$...     

First-principles Investigations on the Magnetic,Electronic, and Optical Properties of Honeycomb-Kagome-Structured Fe $$_{2}$$ O $$_3$$ Monolayer

Journal of Superconductivity and Novel Magnetism - Two-dimensional materials with a novel honeycomb-kagome structure have got a variety of attentions owing to their dramatic properties. In the...     

Identify the Nematic Superconductivity of Topological Superconductor Pd $$_x$$ x Bi $$_2$$ 2 Te $$_3$$ 3 by Angle-dependent Upper Critical Field Measurement

Journal of Superconductivity and Novel Magnetism - Odd-parity superconductivity is recognized as a key ingredient to realize topological superconductivity. In Bi2Se3-based bulk topological...     

Extracting Stray Magnetic Fields from Thin Ferromagnetic Layers in Hybrid Superconducting/Ferromagnetic Heterostructures

Journal of Superconductivity and Novel Magnetism - Hybrid Nb(20)/Cu(5)/Py(2), Nb(20)/Cu(5)/Co(40) and Nb(20)/Cu(d $$_{Cu}$$ )/Py(2)/Cu(5)/Co(40) heterostructures (values in nanometers and d...     

Preparation and electrical properties of sintered oxides composed of Mn1.5Co(0.25+X)Ni(1.25-X)O4 ( $$0 \leqq X \leqq 0.75$$) with a cubic spinel structure

Monophase cubic spinel-type oxides of Mn_1.5Co_(0.25+X)Ni_(1.25-X)O₄ ( ) were prepared through the oxidation of specimens sintered at 1400 °C. The oxides with composition are focused on in this study, as the oxides with composition did not convert into a monophase cubic spinel structure. The electrical conductivity of the sintered bodies was confirmed to increase exponentially with increasing temperature. In the composition range of , both the electrical conductivity and the Seebeck coefficient increased with increasing X. The oxides with composition between were n-type semiconductors, whereas those with were p-type. It was concluded that electrical conduction in the specimens is controlled by small polaron hopping.     

The trace spectra of polynomial bases for $${\mathbb{F}}_{2^{n}}$$

In this paper we study the trace spectra of polynomial bases for over . Shparlinski showed that there exists a polynomial basis having O(log n) elements of trace one. Here we show that for every t ≤ n, there exists a polynomial basis having t + O(log n) elements of trace one. We also study consequences of our results to the existence of irreducible polynomials of certain weights.     

Caustic Pattern of Magnetoelastic Waves in the Vicinity of Magnetoelastic Resonance in Fe $$_{1-x}$$ 1 - x Ga $$_{x}$$ x Crystal

Journal of Superconductivity and Novel Magnetism - The vicinities of two resonance points where longitudinal and transverse elastic waves interact with the magnetic mode are considered. The caustic...     

The AB Transition in Superfluid $$^3$$ 3 He

Journal of Low Temperature Physics - The discovery of superfluidity in $$^3$$ He in 1971, published in 1972, [1, 2] has influenced a wide range of investigations that extend well beyond fermionic...     

Epitaxy of GaN(0001) and GaN(10 $$\bar {1}$$ 1) Layers on Si(100) Substrate

Technical Physics Letters - Two different approaches to epitaxy of 4-μm-thick layers of polar GaN(0001) and semipolar GaN(10 $$\bar {1}$$ 1) on a V-shaped nanostructured Si(100) substrate with...     

Hydrothermal Synthesis of Single-Domain Zinc Ferrite Nanoparticles ( $$\mathrm {ZnFe_{2}O_{4}}$$ ZnFe 2 O 4 ): Structural,Morphological, and Magnetic Studies

Journal of Superconductivity and Novel Magnetism - In order to investigate the size dependence of magnetic properties in the single-domain and superparamagnetic regimes, zinc ferrite $$\mathrm...     

Bi2212 c-Axis Twist Bicrystal and Artificial and Natural Cross-Whisker Josephson Junctions: Strong Evidence for s-Wave Superconductivity and Incoherent c-Axis Tunneling

We discuss the latest data from c-axis twist Josephson junction experiments on Bi₂Sr₂CaCu₂O (Bi2212) bicrystals and on artificially and naturally formed cross whiskers. All three experiments provide strong evidence for a dominant s-wave order parameter for . The bicrystal and natural cross-whisker data also provide strong evidence for incoherent c-axis tunneling across the intrinsic Bi2212 junctions, consistent with a strongly inhomogeneous material.     

Current-Induced Metastable States Close to T $$_{c}$$ c in NbTi Superconducting Bridges

Journal of Superconductivity and Novel Magnetism - We have studied the characteristics of different metastable states in NbTi thin film deposited on sapphire substrate in a region very close to the...