Materials Literature
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Using transmission electron microscopy (TEM) we studied $\mathrm{Ca}{\mathrm{Cu}}_{3}{\mathrm{Ti}}_{4}{\mathrm{O}}_{12}$, an intriguing material that exhibits a huge dielectric response, up to kilohertz frequencies, over a wide range of temperature. Neither in single crystals, nor in polycrystalline samples, including…
We show that the resistivity rho(T) of disordered ferromagnets near, and above, the Curie temperature T_c generically exhibits a stronger anomaly than the scaling-based Fisher-Langer prediction. Treating transport beyond the Boltzmann description, we find that within mean-field theory, dρ/dT exhibits a |T-T_c|^{-1/2}…
We present experimental evidence for cooperative energy transfer from ${\mathrm{Tb}}^{3+}$ to two ${\mathrm{Yb}}^{3+}$ ions and a determination of the energy-transfer rate. Energy transfer from ${\mathrm{Tb}}^{3+}$ to ${\mathrm{Yb}}^{3+}$ was investigated by luminescence measurements on $({\mathrm{Yb}}_{x}{\mathrm{Y}}…
Transport properties of aliovalent-ion-doped BiFeO3 (BFO) thin films have been studied in order to identify the cause of high leakage currents. Doping of 2at.% Ti4+ ions increased the dc resistivity by more than three orders of magnitude. In contrast, doping of 2+ ions such as Ni2+ reduced the dc resistivity by two or…
The strain-induced resistance changes of both SWNT and MWNT films have been studied. Carbon nanotubes in this study were synthesized by hot filament chemical vapor deposition. Experimental results showed that there is a striking piezoresistive effect in carbon nanotube films. The relative change in resistance of carbo…
Single crystals of two-dimensional 2 H - NbSe 2 , which undergo superconducting transition at T c =7.1 K and charge-density wave (CDW) transition at T CDW =30 K , were synthesized. The resistance residual ratio (RRR=R(300 K )/R(8 K )) of the samples from different batches varies from 10 to 30, but the superconducting…
The present work completes and extends our previous reports on the determination of the magnetic ground state and on the strength of the through bond exchange coupling within series of biradicals. This knowledge was subsequently exploited for the analysis of the magnetic interactions in their crystals. We report here…
Ausgehend von Lanthanoidoxiden als Lanthanoidquelle wurden unter Hydrothermalbedingungen Koordinationspolymere synthetisiert, in denen [Ln14(μ6-O)(μ3-OH)20(H2O)8]20+-Cluster (Ln=Y, Gd, Dy) über Isonicotinatliganden mit zwei unterschiedlichen Typen von Kupferzentren verknüpft sind. Das ungewöhnliche Netzwerk dieser iso…
Propagation of light through a thin flat metallic screen containing a hole of twisted shape is sensitive to whether the incident wave is left or right circularly polarized. The transmitted light accrues a component with handedness opposite to the incident wave. The efficiency of polarization conversion depends on the…
Preface / Kingdom of Nanostructures / Quantum Confinement in Low-Dimensional Systems / Resonant Light Reflection, Transmission & Absorption / Intraband Optical Spectroscopy of Nanostructures / Photoluminescence Spectroscopy / Light Scattering / Nonlinear Optics / Photogalvanic Effects / Conclusion / Appendix A: Tables…
Abstract Novel family of molecular glasses based on silicon-containing compounds, α,ω-dimethyloligo(diphenylsilylene)s are synthesized and characterized. Glass-forming properties of these materials tended to have even-odd effect of chain length. The morphology of glassy samples was found to be mainly amorphous with on…
The bonding and vibrational properties of Pd(CO) and Pd(CO)(2) complexes formed at the (100) surface of MgO have been investigated using the gradient-corrected DFT approach and have been compared to the results of infrared and thermal desorption experiments performed on ultrathin MgO films. Two complementary approache…
Very asymmetric mixtures of hard spheres naturally arise in the modellization of colloidal dispersions. Effective potentials have emerged as a powerful tool for describing these systems and have often been employed to extract the phase diagram in both the additive and nonadditive cases. However, most theoretical inves…
The surface-enhanced resonance Raman scattering (SERRS) activity of a statistically significant number of silver nanoparticles has been studied using a correlated SERRS mapping and transmission electron microscopy (TEM) method. TEM allowed the nature of each entity to be directly identified, and the SERRS activity was…
We report density functional theory calculations on six-coordinate ferric-NO ({FeNO}6) porphyrinates that contain either imidazole or imidazolate as the trans axial ligand. Our results show that the sensitivities of the Fe-NO and N-O stretching frequencies to cis and trans influences are directly correlated. In other…
Different potassium salts and zinc(II) and nickel(II) O,O'-dialkyldithiophosphate complexes were studied by solid-state 31P CP/MAS and static NMR and ab initio quantum mechanical calculations. Spectra were obtained at different spinning frequencies, and the intensities of the spinning sidebands were used to estimate t…
The nature of order−disorder transitions in cross-linked diblock copolymer melts was studied using small-angle X-ray scattering (SAXS) and birefringence measurements. Experiments were conducted on cross-linked polystyrene- block -polyisoprene copolymer samples wherein the polyisoprene block was selectively cross-linke…
The compositional and structural rearrangements at the catalyst surface during chemical reactions are issues of great importance for understanding and modeling the catalytic processes. Low-energy electron microscopy and photoelectron spectromicroscopy studies of the real-space structure and composition of a Au-modifie…
The structure of Y Fe 2 D 3.5 at 290 K has been refined in a monoclinic superstructure using synchrotron radiation and neutron diffraction experiments. The evolution of the 57 Fe Mössbauer spectra versus temperature for ZrFe 2 D x and Y Fe 2 D x deuterides with large deuterium content has been studied. For x = 3.5 bot…
Two novel dinuclear copper(II) complexes containing four spin carriers have been synthesized and characterized structurally and magnetically. These complexes are formulated as [Cu 2 (apox)(NIT-4Py) 2 ](ClO 4 ) 2 ·2H 2 O ( 1 ) and [Cu 2 (apox)(NIT-2Py) 2 ](ClO 4 ) 2 ( 2 ), where apox = N, N ‘-bis(3-aminopropyl) oxamido…