We report Raman-scattering studies of polycrystalline ${\mathrm{BaTiO}}_{3}$ under pressure up to 8.6 GPa. Our data show evidence for two structural phase transformations, one at around 2 GPa which corresponds the previously reported tetragonal cubic transition and a new near 5 The persistence strong Raman lines well beyond suggests presence significant disorder in high-pressure phase. In case samples, may arise not only from off-center positions Ti atoms as was proposed earlier single...

We report electrical characterization of monolayer molybdenum disulfide (MoS2) devices using a thin layer polymer electrolyte consisting poly(ethylene oxide) (PEO) and lithium perchlorate (LiClO4) as both contact-barrier reducer channel mobility booster. find that bare MoS2 (without electrolyte) fabricated on Si/SiO2 have low large contact resistance, which severely limit the field-effect devices. A PEO/ LiClO4 deposited top not only substantially reduces resistance but also boost mobility,...

We have synthesized a range of transition-metal-doped BiFeO(3) thin films on conducting silicon substrates using spin-coating technique from metal-organic precursor solutions. Bismuth, iron and transition-metal-organic solutions were mixed in the appropriate ratios to produce 3% samples. X-ray diffraction studies show that samples annealed nitrogen atmosphere crystallize rhombohedrally distorted structure with no evidence for any ferromagnetic secondary phase formation. find disappearance...

We report ferromagnetism above $300\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ in $\mathrm{Zn}\mathrm{O}:x\mathrm{Cu}$ ($x$ at. %) sputtered thin films. For $x<1$, a large magnetic moment of $1.6\phantom{\rule{0.3em}{0ex}}{\ensuremath{\mu}}_{B}∕\mathrm{Cu}$ was observed, which decreases monotonically with increasing $x$. find evidence that the ferromagnetic is due to Cu-O planar nanophase inclusions ZnO basal planes. The presence CuO confirmed by transmission electron microscopy, x-ray...

Abstract This paper introduces a new robust method for the removal of background tissue fluorescence from Raman spectra. spectra consist noise, and scattering. In order to extract scattering, both noise must be removed, ideally without human intervention preserving original data. We describe rationale behind our subtraction method, determine parameters validate it using phantom against other methods currently used. also statistically compare residual mean square (RMS) with...

Abstract Raman spectroscopy shows potential in differentiating tumors from normal tissue. We used with near‐infrared light excitation to study breast tissue and 11 mice injected a cancer cell line. Spectra were collected 17 tumors, 18 samples of adjacent lymph nodes, the contralateral its nodes. Discriminant function analysis was for classification principal component scores as input data. Tissues examined by microscopy following formalin fixation hematoxylin eosin staining. histology agreed...

Flexible inorganic-organic magneto-electric (ME) nanocomposite films (PVDF, PVDF-GO, PVDF-Fe3O4 and PVDF-GO-Fe3O4), composed of well-dispersed graphene oxide (GO 5 wt%) magnetic Fe3O4 nanoparticles (5 embedded into a poly(vinylidene-fluoride) (PVDF) matrix, have been prepared by solvent casting route. The magnetic, ferroelectric, dielectric, magneto-dielectric (MD) coupling structural properties these systematically investigated. Magnetic (Ms = 2.21 emu g(-1)) ferroelectric (P 0.065 μC...

We have studied the temperature dependence of Raman spectra ceramic bulk and thin-film samples polycrystalline ${\mathrm{Ba}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{TiO}}_{3}$ $(x=0,$ 0.1, 0.2, 0.3) in range between room 350 \ifmmode^\circ\else\textdegree\fi{}C. The ferroelectric to paraelectric phase-transition temperatures ${(T}_{C})$ been estimated from loss intensity for several phonon modes belonging tetragonal phase when transform cubic phase. Similar single crystalline...

The optical properties, Raman spectra, and magnetization of Zn1−xCoxO (0≤x<0.1) thin films are reported. Optical transmission spectra confirm the substitution Co2+ cations for Zn2+ ions at tetrahedral sites ZnO. annealed in air show an additional broad vibrational mode, attributed to disordered –Zn–O–Co– local vibrations. These modes disappear on vacuum annealing, suggesting formation oxygen vacancies close dopant (–Zn––Co–). Magnetization measurements that air-annealed lack significant...

We present evidence for spin polarized charge carriers in In$_2$O$_3$ films. Both and Cr doped films exhibit room temperature ferromagnetism after vacuum annealing, with a saturation moment of approximately 0.5 emu/cm$^3$. used Point Contact Andreev Reflection measurements to directly determine the polarization, which was found be 50$\pm$5% both compositions. These results are consistent suggestions that observed certain oxide semiconductors may carrier mediated.

We report the structural and optical properties of xSnO2–yFe2O3 nanocrystalline composite thin films. SnO2 Fe2O3 exhibit strong phase separation instability their particle size crystallinity are tunable by changing composition annealing temperature. The bandgap for these composites continuously increases from 2.3 to 3.89 eV. discuss increasing values in terms quantum confinement effect manifested decreasing crystallites. method provides a generic approach tuning nanocomposite systems.

Rate of heat generated by magnetic nanoparticles in a ferrofluid is affected their properties, temperature, and viscosity the carrier liquid. We have investigated temperature dependent hyperthermia ferrofluids, consisting dextran coated superparamagnetic Fe3O4 nanoparticles, subjected to external fields various frequencies (188–375 kHz) amplitudes (140–235 Oe). Transmission electron microscopy measurements show that are polydispersed with mean diameter 13.8 ± 3.1 nm. The fitting experimental...

Flexible and self-standing polyvinylidene fluoride (PVDF) films loaded with nanofillers, reduced graphene oxide (RGO), zinc (ZnO) magnetic iron (Fe₃O₄) nanoparticles, were prepared by a solvent casting method.

$\ensuremath{\gamma}\text{\ensuremath{-}}{\mathrm{Fe}}_{2}{\mathrm{O}}_{3}$ magnetic nanoparticles ranging in average diameter from $3\phantom{\rule{0.3em}{0ex}}\text{to}\phantom{\rule{0.3em}{0ex}}10\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ were synthesized into a polystyrene resin matrix by an ion-exchange method and characterized X-ray diffraction (XRD), transmission electron microscopy (TEM), M\"ossbauer spectroscopy, SQUID magnetometry. The particle size as determined XRD TEM was found to...

Epitaxial Al1−xInxN thin films with 0⩽x⩽1 have been grown by plasma source molecular beam epitaxy on sapphire (0001) substrates at a low temperature of 375 °C. Both reflection high-energy electron diffraction and x-ray measurements confirm the c-plane growth following epitaxial relations: nitride [0001] ∥ 〈011̄0〉 〈21̄1̄0〉. However, degree crystalline mosaicity compositional fluctuation increase increasing x. The observed direct energy band gap, determined using optical transmission show...

The low-temperature dynamics of a noninteracting magnetic nanoparticle system ($\ensuremath{\gamma}\text{\ensuremath{-}}{\mathrm{Fe}}_{2}{\mathrm{O}}_{3}$-alginate composite with an average size $4\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$) has been studied by superconducting quantum interference device magnetization measurements. Using different temperature and field protocols memory phenomena have observed in the dc relaxation this at temperatures below its blocking...

We have studied the ${A}_{1}(\mathrm{LO})$ structure of InN thin films from a low $({n}_{e}=6.7\ifmmode\times\else\texttimes\fi{}{10}^{17}∕{\mathrm{cm}}^{3})$ to very high $({n}_{e}=9.6\ifmmode\times\else\texttimes\fi{}{10}^{20}∕{\mathrm{cm}}^{3})$ carrier concentration using Raman scattering experiments. Theoretically we investigated this wave vector $\mathbf{q}$ dependent dielectric function $\ensuremath{\epsilon}(q,\ensuremath{\omega})$ which takes into account coupling...