相关论文: Strong microwave absorption observed in dielectric…

We report microwave magnetoabsorption (P) at room temperature in R0.6Sr0.4MnO3 (R = Pr and Nd) samples. P as a function of dc magnetic field (-2.5 kOe to +2.5 kOe) was measured for a broad frequency range (f = 0.1 - 4 GHz) of microwave…

We have measured optical reflectivity of Li and Ti doped NiO (LTNO) in the infrared range at various temperatures. A Drude-like absorption is found at low energy, $\omega <$ 100 cm$^{-1}$ and its spectral weight increases substantially as…

We propose a thin, compact, broadband, polarization and angle insensitive metamaterial absorber based on a tungsten reflector, silicon spacer and a top pattern composed of a double square-like ring resonator utilizing nickel(Ni). In such a…

High-permittivity dielectric particles with resonant magnetic properties are being explored as constitutive elements of new metamaterials and devices in the microwave regime. Magnetic properties of low-loss dielectric nanoparticles in the…

Magnetic properties of the Ni$_{0.5}$Zn$_{0.5}$Fe$_2$O$_4$ (NZF) spinel ferrite ceramics were studied over a broad frequency range (1 MHz - 50 GHz). Between 10 MHz and 2 GHz, strong temperature-dependent resonance-like magnetic permeability…

The high-pressure synthesized quasi-one-dimensional compounds NaMn$_2$O$_4$ and Li$_{0.92}$Mn$_2$O$_4$ are both antiferromagnetic insulators, and here their atomic and magnetic structures were investigated using neutron powder diffraction.…

Material absorption is a key limitation in nanophotonic systems; however, its characterization is often obscured by scattering and diffraction loss. Here we show that nanomechanical frequency spectroscopy can be used to characterize the…

The electromagnetic properties and microwave absorption capabilities are studied in an anechoic chamber under real radar conditions for mono and bilayer composite samples consisting of a polymeric matrix and a magnetic powder filler, either…

Strong resonant enhancements of the charge-order and spin-order superstructure-diffraction intensities in La1.8Sr0.2NiO4 are observed when x-ray energies in the vicinity of the Ni L2,3 absorption edges are used. The pronounced photon-energy…

Radio absorptive materials (RAMs) are key elements for receivers in the millimeter-wave range. For astronomical applications, cryogenic receivers are widely used to achieve a high-sensitivity. These cryogenic receivers, in particular the…

We are reporting the dielectric response of La1.5Sr0.5NiO4, a system that presents a charge-ordered state above room temperature and a rearrangement of its charge-order pattern in the temperature region 160-200 K. A careful analysis of the…

Representative compounds of the new family of magnetic materials Gd5-xNdxSi4 were analyzed by X-ray diffraction at the XRD1 beamline at LNLS. To reduce X-ray absorption, thin layers of the powder samples were mounted outside the capillaries…

We report on the infrared absorption spectra of three oxides where charged superlattices have been recently observed in diffraction experiments. In La$_{1.67}$Sr$_{0.33}$NiO$_4$, polaron localization is found to suppress the low-energy…

We develop ZnO/p-Si photodetectors by atomic layer deposition (ALD) of ZnO thin films on laser-microstructured silicon and we investigate their electrical and optical behavior, demonstrating high sensitivity and broadband operation.…

We report the detection of paramagnetic resonance in the double perovskite La2NiMnO6 at room temperature for microwave magnetic fields with frequencies, f = 1 GHz to 5 GHz, using two cavity-less methods. We use an indirect impedance method…

We have carried out far-infrared (far-IR) transmission measurements on the ligand stabilized Au55 nanoparticles dispersed in Teflon at volume fractions ranging from 0.2% to 1%. Instead of a series of peaks which might arise from the…

$^{75}$As and $^{139}$La field-swept NMR spectra were obtained for the novel weakly itinerant ferromagnet LaCoAsO with 2D layered structure above the Curie temperature of 55 K. By analyzing NMR spectra, temperature dependences of Knight…

Ni coated SiO2 and SiO2 coated Ni composite particles with core-shell structures were designed, prepared and their microwave absorption properties were characterized. The comparison study of the shell effect on the effective electromagnetic…

We present spectroscopic, photometric and astrometric observations of four bright L dwarfs identified in the course of the 2MASS near-infrared survey. Our spectroscopic data extend to wavelengths shortward of 5000\AA in the L0 dwarf…

The complex permeability of an iron-oxide nanosuspension has been measured as a function of magnetic field strength at RF and microwave frequencies using a loop-gap resonator. The particles were suspended in water and had an 8-nm diameter…