Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
The metal-insulator transition is characterized as a single peak in the temperature-dependent resistivity measurements; exceptions to this have never been seen in any single crystal material system. We show that by reducing a single crystal manganite thin film to a wire with a width comparable to the mesoscopic phase-…
A novel method for controlling nanowire magnetic properties and growth from filling time profile is presented. The wires are grown with an electrodeposition method ("Template synthesis") with a wide selection of pore diameters. We show that stray-fields presence in ferromagnetic nanowires are entirely dependent on the…
We present the design, fabrication, and measurement of a dual-band planar metamaterial with two distinct electric resonances at 1.0 and 1.2 THz, as a step towards the development of frequency agile or broadband THz materials and devices. A method of defining the effective thickness of the metamaterial layer is introdu…
Point defects in metal oxides such as ${\text{TiO}}_{2}$ are key to their applications in numerous technologies. The investigation of thermally induced nonstoichiometry in ${\text{TiO}}_{2}$ is complicated by the difficulties in preparing and determining a desired degree of nonstoichiometry. We study controlled self-d…
The magnetization dynamics of the triangular lattice of Ising spin chains is investigated in the framework of a two-dimensional model. The rigid chains are assumed to interact with the nearest neighboring chains, an external magnetic field, and a heat reservoir that causes the chains to change their states randomly wi…
Ultrafast degenerate pump-probe experiments performed on a free standing film of double walled carbon nanotubes near the first metallic transition energy of outer tube show ultrafast ($97 fs$) photobleaching followed by a photo-induced absorption with a slow relaxation of $1.8 ps$. Femtosecond closed and open aperture…
We carry out a theoretical investigation to clarify the dynamic property of photo-created nano-sized ferroelectric cluster observed in the paraelectric BaTiO3 as a real time correlation of speckle pattern between two soft X-ray laser pulses, at just above the paraelectric-ferroelectric phase transition temperature. Ba…
A low-temperature specific heat study has been performed on the insulating giant dielectric constant material CaCu 3 Ti 4 O 12 and two related compounds, Bi 2/3 Cu 3 Ti 4 O 12 and La 0.5 Na 0.5 Cu 3 Ti 4 O 12 , from 0.6 to 10 K. From analyzing the specific heat data in a very low-temperature range, 0.6–1.5 K, and mode…
Graphene, a single sheet of graphite with honeycomb lattice structure, has massless carriers with tunable density and polarity. We investigate the ground-state phase diagram of two graphene sheets (embedded in a dielectric), separated by distance $d$ where the top layer has electrons and the bottom layer has holes, us…
Two new phases YbCu4.4 and YbCu4.25 are found as a result of careful phase diagram investigations. Between the congruent and peritectic formation of YbCu4.5 and YbCu3.5, respectively, the phases YbCu4.4 and YbCu4.25 are formed peritectically at 934(2)degC and 931(3)degC. Crystal growth was realised using a Bridgman te…
We show how the capillary filling of microchannels is affected by posts or ridges on the sides of the channels. Ridges perpendicular to the flow direction introduce contact line pinning, which slows, or sometimes prevents, filling, whereas ridges parallel to the flow provide extra surface that may enhance filling. Pat…
Collaboration between Kaiser Optical Systems, Inc. and the Department of Physics and Astronomy at Johns Hopkins University has resulted in the construction of volume phase holographic (VPH) transmission gratings that were subsequently tested in a cryogenic environment. VPH gratings were built on two popular optical gl…
Piezoelectric contributions from mobile 90° domains are locally activated by electrical training of a PZT thin film. The high response state of 160 pm V−1 corresponds well with theoretical predictions. This state relaxed at modest trainings within minutes but was stabilized after extensive training. Our findings indic…
Although ZrB2 has some excellent performances, it is difficult to prepare the high relative-density ZrB2 ceramics, which limits the application of ZrB2 materials. To obtain higher relative-density ZrB2 ceramics for increasing the good oxidation resistance, YAG/ZrB2 multiphase ceramics is prepared with the spark plasma…
We present an improved version of the Jiles-Atherton model for least square identification. We first use a simplified anhysteretic magnetization model to provide simple estimates of the initial parameters. Then we perform a normalization of sensitivity functions to improve the convergence of the Levenberg-Marquardt al…
We report on electroluminescent P-I-N diodes containing silicon nanocrystals embedded in an amorphous silicon carbon matrix as emitting material. The as-deposited devices mostly contain amorphous Si nanoparticles and emit weakly in the IR. After a forming process consisting of the application of a high current density…
Abstract In this study, poly(ethylene terephthalate) (PET)/attapulgite (AT) nanocomposites were prepared through the in situ polymerization of terephthalic acid, ethylene glycol, and AT, which was not premodified. By means of this new method, PET chains were successfully grafted onto the surface of AT, and this was co…
Selective deposition of nano-β-SiC on non-{100} diamond faces has been observed in a microwave plasma chemical vapor deposition process due to the presence of Si(CH3)4 in the gas phase. The process allows only the growth of diamond starting crystals whose [001] is normal to the film surface and interrupts the growth o…
We have measured the electrical resistivity, heat capacity, and thermal conductivity of (La1−xNdx)0.7Pb0.3MnO3 single crystals. While the increase in x results in the change in crystal symmetry, reduction in the Curie temperature TC, and large enhancement of magnetoresistance, the magnitude of the dip in thermal cond…
The revival of multiferroics is motivated by their exciting physics and their ability to bring novel functionalities to a number of technological fields such as spintronics. The lack of room temperature ferroelectric ferromagnets is a problem and has driven most of the attention thus far to BiFeO$_3$, a ferroelectric…