Herein, we report the synthesis of multiscale nanostructured p-type (Bi,Sb)(2)Te(3) bulk materials by melt-spinning single elements Bi, Sb, and Te followed a spark plasma sintering process. The samples that were most optimized with resulting composition (Bi(0.48)Sb(1.52)Te(3)) specific nanostructures showed an increase approximately 50% or more in figure merit, ZT, over commercial material between 280 475 K, making it suitable for applications related to both power generation refrigeration....

Polarized small-angle neutron scattering studies of single-crystalline multiferroic BiFeO(3) reveal a long-wavelength spin density wave generated by ∼1° canting the spins out rotation plane antiferromagnetic cycloidal order. This signifies weak ferromagnetism within mesoscopic regions dimension 0.03 microns along [110], to several [111], confirming long-standing theoretical prediction. The average local magnetization is 0.06 μ(B)/Fe. Our results provide an indication intrinsic macroscopic be...

A new development in small-angle neutron scattering with polarization analysis allows us to directly extract the average spatial distributions of magnetic moments and their correlations three-dimensional directional sensitivity any field. Applied a collection spherical magnetite nanoparticles 9.0 nm diameter, this enhanced method reveals uniformly canted, magnetically active shells nominally saturating field 1.2 T. The shell thickness depends on temperature, it disappears altogether when...

Superconductivity in the iron pnictides develops near antiferromagnetism, and antiferromagnetic (AF) phase appears to overlap with superconducting some materials such as ${\mathrm{BaFe}}_{2\ensuremath{-}x}{T}_{x}{\mathrm{As}}_{2}$ (where $T=\mathrm{Co}$ or Ni). Here we use neutron scattering demonstrate that genuine long-range AF order superconductivity do not coexist ${\mathrm{BaFe}}_{2\ensuremath{-}x}{\mathrm{Ni}}_{x}{\mathrm{As}}_{2}$ optimal superconductivity. In addition, find a...

We study the structural and magnetic orders in electron-doped ${\mathrm{BaFe}}_{2\ensuremath{-}x}{\mathrm{Ni}}_{x}{\mathrm{As}}_{2}$ by high-resolution synchrotron x-ray neutron scatterings. Upon Ni doping $x$, nearly simultaneous tetragonal-to-orthorhombic (${T}_{s}$) antiferromagnetic (${T}_{N}$) phase transitions ${\mathrm{BaFe}}_{2}{\mathrm{As}}_{2}$ are gradually suppressed separated, resulting ${T}_{s}>{T}_{N}$ with increasing as was previously observed. However, temperature separation...

Iron-gallium alloys ${\mathrm{Fe}}_{1\ensuremath{-}x}{\mathrm{Ga}}_{x}$ exhibit an exceptional increase in magnetostriction with gallium content. We present small-angle neutron scattering investigations on a ${\mathrm{Fe}}_{0.81}{\mathrm{Ga}}_{0.19}$ single crystal. uncover heterogeneities average spacing of 15 nm and magnetizations distinct from the matrix. The moments around are observed to reorient applied magnetic field or mechanical strain. discuss possible roles played by nanoscale...

The pyrochlore material Yb2Ti2O7 displays unexpected quasi-two-dimensional (2D) magnetic correlations within a cubic lattice environment at low temperatures, before entering an exotic disordered ground state below T=265mK. We report neutron scattering measurements of the thermal evolution 2D spin in space and time. Short range three dimensional (3D) develop 400 mK, accompanied by suppression quasi-elastic (QE) ~ 0.2 meV. These show slowly fluctuating with spins correlated over short...

The degradation in magnetic properties very thin film complex oxides is studied using SrTiO3(001)/La1-xSrxCoO3, providing unequivocal evidence for nanoscopic interfacial phase separation. Electron microscopy and spectroscopy reveal that this occurs due to inhomogeneity local hole doping, driven by subtle, depthwise variations the Sr O stoichiometry. Simple thermodynamic structural arguments origin of these are provided. Detailed facts importance specialist readers published as "Supporting...

The structure and properties of the ferromagnet ${\mathrm{Tb}}_{1\ensuremath{-}x}{\mathrm{Dy}}_{x}{\mathrm{Fe}}_{2}$ are explored through morphotropic phase boundary (MPB) separating ferroic phases differing symmetry. Our synchrotron data support a first order structural transition, with broadening MPB width at higher temperatures. optimal point for magnetomechanical applications is not centered on but lies rhombohedral side, where high striction majority combines softened anisotropy MPB. We...

The calculation of neutron reflectivity from raw time-of-flight data including instrumental corrections and an improved resolution is presented. theoretical calculations are compared with experimental measured on the vertical sample plane reflectometer D17 horizontal FIGARO at Institut Laue–Langevin (ILL), Grenoble, France. This article comprises mathematical body data-reduction software COSMOS which used FIGARO.

The nature of the spin-flop (SF) transition in magnetoelectric quasi-2D Heisenberg system LiMnPO${}_{4}$ is studied fields applied along $a$ axis. A refinement magnetic structure using neutron diffraction data SF phase reveals that spins reorient from being parallel to axis be nearly $c$ at between 4 and 4.7 T, depending on temperature. low-field antiferromagnetic boundary shown join line tangentially so-called bicritical point, where there a suppression ordering At field, we observe an...

Neutron diffraction and calorimetric measurements are used to study the field-induced quantum phase transition in piperazinium-Cu${}_{2}$(Cl${}_{1\ensuremath{-}x}$Br${}_{x}$)${}_{6}$ ($x=0$, $3.5$$%$, $7.5$$%$), a prototypical antiferromagnet with random bonds. The critical indexes $\ensuremath{\varphi}$ $\ensuremath{\beta}$ determined. findings contradict some original predictions for Bose glass based on assumption $z=d$, but consistent recent theoretical results implying...

We report significant details of the magnetic structure and spin dynamics ${\mathrm{LiFePO}}_{4}$ obtained by single-crystal neutron scattering. Our results confirm a previously reported collinear rotation spins away from principal $b$ axis, they determine that is toward $a$ axis. In addition, we find spin-canting component along $c$. The possible causes these components are discussed, their significance for magnetoelectric effect analyzed. Inelastic scattering three directions reveals...

We have performed polarized and unpolarized small angle neutron scattering experiments on single crystals of HoMnO3 found that an increase in magnetic at low momentum transfers begins upon cooling through temperatures close to the spin reorientation transition TSR ~ 40 K. attribute uncompensated magnetization arising within antiferromagnetic domain walls. Polarized while applying electric field show suppresses below T 50 K, indicating affects via walls rather than a change bulk order.

The morphology of the superconducting flux line lattice (FLL) Nb comprises gradual variations with various lock-in transitions and symmetry breaking rotations. We report a comprehensive small-angle neutron scattering study FLL in an ultrapure single crystal as function orientation applied magnetic field. attribute general its to three dominant mechanisms; first, nonlocal contributions, second, transition between open closed Fermi surface sheets and, third, intermediate mixed state Meissner...

The disordered flux line lattice in single crystals of the slightly overdoped ${\text{BaFe}}_{2\ensuremath{-}x}{\text{Co}}_{x}{\text{As}}_{2}$ ($x=0.19$, ${T}_{\text{c}}=23\text{ }\text{K}$) superconductor is studied by magnetization measurements, small-angle neutron scattering, and magnetic force microscopy (MFM). In whole range fields up to 9 T, vortex pinning precludes formation an ordered Abrikosov lattice. Instead, a vitreous phase (vortex glass) with short-range hexagonal order...

We report an extensive investigation of magnetic vortex lattice (VL) structures in single crystals pure niobium with the field applied parallel to a fourfold symmetry axis, so as induce frustration between cubic crystal and hexagonal VL coordination expected isotropic situation. observe new phase transitions; all phases observed (including those exactly square unit cell) spontaneously break some symmetry. One even has lowest possible two-dimensional Bravais lattice. This is quite unlike...

This paper investigates the origin of large magnetostriction in Fe–Ga alloys using small-angle neutron scattering (SANS) and Kerr microscopy. The SANS data for a single-crystal, electron irradiated, quenched Fe81Ga19 sample under externally applied magnetic elastic fields revealed existence magnetostrictive nanoclusters spaced at ∼15 nm apart that have different magnetization than A2 matrix. Combining results orientation obtained from domain images microscope, it appears contribute...

CeCoIn5 is a heavy fermion Type-II superconductor which exhibits clear indications of Pauli-limited superconductivity. A variety measurements give evidence for transition at high magnetic fields inside the superconducting state, when field applied either parallel to or perpendicular c axis. When axis, antiferromagnetic order observed on high-field side transition, with wavevector (q q 0.5), where = 0.44 reciprocal lattice units. We show that this remains as rotated out basal plane, but...

Adding impurities or defects destroys crystalline order. Occasionally, however, extraordinary behaviour emerges that cannot be explained by perturbing the ordered state. One example is Kondo effect, where magnetic in metals drastically alter temperature dependence of resistivity. In Type-II superconductors, disorder generally works to pin vortices, giving zero resistivity below a critical current jc. However, peaks have been observed and field dependences This peak effect difficult explain...

CaFe_{2}O_{4} is a S=5/2 anisotropic antiferromagnet based upon zig-zag chains having two competing magnetic structures, denoted as the A (↑↑↓↓) and B (↑↓↑↓) phases, which differ by c-axis stacking of ferromagnetic stripes. We apply neutron scattering to demonstrate that phase order parameters result in antiphase boundaries along c freeze on time scale ∼1 ns at onset 200 K. Using high resolution spectroscopy, we find quantized spin wave levels measure 9 such excitations localized regions...

High-purity niobium exhibits a surprisingly rich assortment of vortex lattice (VL) structures for fields applied parallel to fourfold symmetry axis, with all observed VL phases made up degenerate domains that spontaneously break some crystal symmetry. Yet single regular hexagonal domain is at temperatures and threefold axis. We report detailed investigation the transition between these lush barren landscapes, discovering new phase transitions high fields. show number relative population...