Materials Literature
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Abstract Melt‐crystallized, low molecular weight poly( L ‐lactic acid) (PLLA) consisting of α crystals was uniaxially drawn by solid‐state extrusion at an extrusion temperature ( T ext ) of 130–170 °C. A series of extrusion‐drawn samples were prepared at an optimum T ext value of 170 °C, slightly below the melting tem…
The crystal structure and the magnetic properties of the W1-xNbxO3-d, (x<0.03) system have been investigated. In contrast to the orthorhombic diamagnetic WO3, the material with x=0.01 is paramagnetic down to 5 K. Introducing of 2.5 at. % of Nb into WO3 leads to a tetragonal structure and to a weak itinerant ferromagne…
The present study summerizes magnetic and Mossbauer measurements on ceramic Li2MO3 M= Mn, Ru and Ir and the mixed Li2(Mn1-xRux)O3 materials, which show many of the features reflecting to antiferromagnetic ordering or to existence of paramagnetic states. Li2IrO3 and Li2RuO3 are paramagnetic down to 5 K. Li2(Mn1-xRux)O3…
We have investigated the thermoelasticity of body-centered cubic (bcc) tantalum from first principles by using the linearized augmented plane wave (LAPW) and mixed--basis pseudopotential methods for pressures up to 400 GPa and temperatures up to 10000 K. Electronic excitation contributions to the free energy were incl…
Diffuse scattering around the (110) reciprocal lattice point has been investigated by elastic neutron scattering in the paraelectric and relaxor phases of the disordered complex perovskite crystal $\mathrm{Pb}({\mathrm{Zn}}_{1/3}{\mathrm{Nb}}_{2/3}){\mathrm{O}}_{3}$ (PZN). The appearance of a diffuse intensity peak in…
Dipole-dipole interactions in a square planar array of sub-micron magnetic disks (magnetic dots) have been studied theoretically. Under a normal magnetic field the ground-state of the array undergoes many structural transitions between the limiting chessboard antiferromagnetic state at zero field and the ferromagnet a…
This letter presents p-type metal–oxide–semiconductor (PMOS) and complementary metal–oxide–semiconductor (CMOS) inverters based on single-walled carbon nanotube field-effect transistors. The device structures consist of carbon nanotubes grown via a chemical-vapor deposition method and contacted by two metallic source/…
A microelectromagnet matrix and a ring trap that position and control magnetic nanoparticles are demonstrated. They consist of multiple layers of lithographically defined Au wires separated by transparent, insulating polyimide layers on sapphire substrates. Magnetic field patterns produced by these devices allow micro…
We have calculated the ideal shear strength and ideal tensile strength of C, Si, and Ge in the diamond structure. We find ideal shear strengths of 95 GPa, 6.5 GPa, and 4.5 GPa, and ideal tensile strengths of 95 GPa, 23 GPa, and 14 GPa for C, Si and Ge respectively. The shear calculation is performed on the ${111}$ sli…
A system of ferromagnetic β phase Ni–Co–Al alloys with an ordered B2 structure that exhibits the shape memory effect has been developed. The alloys of this system within the composition range Ni (30–45 at. %) Co–(27–32 at. %) Al, undergo a paramagnetic/ferromagnetic transition as well as a thermoelastic martensitic tr…
A giant magnetocaloric effect was found in MnAs, which undergoes a first-order ferromagnetic to paramagnetic transition at 318 K. The magnetic entropy change caused by a magnetic field of 5 T is as large as 30 J/K kg at the maximum value, which exceeds that of conventional magnetic refrigerant materials by a factor of…
Abstract The curing conditions (such as temperature and time) and material properties such as the TCE (thermal coefficient of expansion), Tg (glass transition temperature), storage modulus, tangent delta (tan δ), and moisture absorption of two different epoxy materials from two different vendors are measured. Emphasis…
Abstract High strain actuation can be obtained by engineering the crystallographic texture of piezoelectric ceramics. Single crystal piezoelectrics have significantly improved strain performance because crystal orientation can be controlled during use — their highly perfect lattice greatly simplifies the crystal orien…
We show how to adapt the quasi-Newton method to the electronic-structure calculations using systematic basis sets. Our implementation requires less iterations than the conjugate gradient method, while the computational cost per iteration is much lower. The memory usage is also quite modest, thanks to the efficient rep…
Copper(II) selenate pentahydrate is isotypic with its sulfate analogue. All atoms are on general positions except Cu1 and Cu2 (both with site symmetry \overline 1). The Jahn–Teller distortion of the CuO2(H2O)4 `octahedra' is slightly less pronounced than in the sulfate analogue. The average Se—O bond length is 1.640 Å.
Accurate heat capacities of the single-molecule magnet [Mn(12)O(12)(O(2)CEt)(16)(H(2)O)(3)] were measured from 0.3 to 311 K by adiabatic calorimetry without an external magnetic field. Heat-capacity anomalies were separated by assuming several contributions including lattice vibration, magnetic anisotropy, and hyperfi…
We present a procedure for the characterization and the linearization of the photoresist response to UV exposure for application to the gray-scale fabrication of diffractive optical elements. A simple and reliable model is presented as part of the characterization procedure. Application to the fabrication of surface-r…
MOCVD has been applied to the first successful deposition of CeO2 〈100〉 oriented films on no-rolled Hastelloy C276. The presently found columnar grain morphologies have been related to the zone model proposed by Mochvan and Demchishin for physical vapor deposition processes. The fiber texture strongly depends on the d…
The low-frequency dynamics of the globular protein β-lactoglobulin has been investigated by inelastic neutron scattering, on both dry and D 2 O-hydrated samples. Both the dynamic structure factor and the density of states display an excess of vibrational modes with respect to the Debye level, with such an excess being…
A binary diffractive optical element, acting as a polarizing beam splitter, is proposed and analyzed. It behaves like a transmissive blazed grating, working on the first or the second diffraction order, depending on the polarization state of the incident radiation. The grating-phase profile required for both polarizat…