Cyclic Tension Induced Pattern Formation on [001] Single-Crystal Aluminum Foil

Cyclic tension of (100)[001]-oriented single-crystal aluminum foils with the frequency 5 Hz forms a tweed pattern. Its period is several microns and increases by a factor of 1.5 in the temperature range 233–363 K. A model is proposed for structural relaxation of the medium on spatial and time meso- and macroscales under cyclic loading. Conditions under which a steady pattern forms are found based on the analysis of kinetic equations. The number of bands in the steady pattern is found to be related to the strain rate. The process activation energy is determined.

Microstructural Characterization of a Single Crystal Copper Rod Using Monochromatic Neutron Radiography Scan and Tomography: A Test Experiment

This paper reports the analysis of a single crystal copper rod aiming to characterize the microstructural features related to the homogeneity of the single crystal growth and the presence, shape and extension of spatially distributed misaligned grains or areas. The analytical method used for such analysis is wavelength scan neutron radiography and monochromatic neutron tomography. Such methods allow determination of the extent of differently oriented single crystal areas, identifying the most part of the rod volume as a single domain. It was also possible to characterize the spatial distribution and the degree of alignment of local point-like or extended defects.

Temperature and Electric Field Dependent Phase Transformations in [001] PMN-PT Single Crystal

The capacitance of (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-xPT) [001]-oriented single crystal was examined as a function of temperature and applied external dc electric field. The phase transition temperatures under the applied electric field were measured upon cooling the crystal (zero-field heating field-cooling condition) from paraelectric cubic phase. From these data, temperature versus electric field phase diagram of PMN-xPT crystal have been constructed and discussed.

Effect of grain boundaries in La0.84Sr0.16CoO3−δ on oxygen diffusivity and surface exchange kinetics

The 16O/18O oxygen exchange kinetics between the gas phase and the oriented single crystal and polycrystalline specimen has been studied; the rates of individual stages of oxygen exchange have been calculated and discussed.

Synthesis, Characterization, and Magnetoresistive Properties of the Epitaxial Pd0.96Fe0.04/VN/Pd0.92Fe0.08 Superconducting Spin-Valve Heterostructure

A thin-film superconductor(S)/ferromagnet(F) F1/S/F2-type Pd0.96Fe0.04(20 nm)/VN(30 nm)/Pd0.92Fe0.08(12 nm) heteroepitaxial structure was synthesized on (001)-oriented single-crystal MgO substrate utilizing a combination of the reactive magnetron sputtering and the molecular-beam epitaxy techniques in ultrahigh vacuum conditions. The reference VN film, Pd0.96Fe0.04/VN, and VN/Pd0.92Fe0.08 bilayers were grown in one run with the target sample. In-situ low-energy electron diffraction and ex-situ X-ray diffraction investigations approved that all the Pd1−xFex and VN layers in the series grew epitaxial in a cube-on-cube mode. Electric resistance measurements demonstrated sharp transitions to the superconducting state with the critical temperature reducing gradually from 7.7 to 5.4 K in the sequence of the VN film, Pd0.96Fe0.04/VN, VN/Pd0.92Fe0.08, and Pd0.96Fe0.04/VN/Pd0.92Fe0.08 heterostructures due to the superconductor/ferromagnet proximity effect. Transition width increased in the same sequence from 21 to 40 mK. Magnetoresistance studies of the trilayer Pd0.96Fe0.04/VN/Pd0.92Fe0.08 sample revealed a superconducting spin-valve effect upon switching between the parallel and antiparallel magnetic configurations, and anomalies associated with the magnetic moment reversals of the ferromagnetic Pd0.92Fe0.08 and Pd0.96Fe0.04 alloy layers. The moderate critical temperature suppression and manifestations of superconducting spin-valve properties make this kind of material promising for superconducting spintronics applications.

Double Perovskite Bi2FeCrO6 Thin Films for Photovoltaics

High-quality BFCO films with smooth morphology were deposited on (001)-oriented single crystal substrates by pulsed-laser deposition. The perfect ferroelectric nature of the BFCO films were probed by PFM and electrical P-E hysteresis measurements and the obtained saturated remeanent polarization value reaches up to 60 μC/cm2. Besides, BFCO films show relatively low bandgap of 2.5 eV, can absorb the sunlight and convert the solar energy to electrically energy effectively. A photocurrent of 1.2 mA/cm2 and an open-circuit voltage of about 0.53 V were obtained under AM1.5G illumination. The results mainfest the BFCO a potiential material for multifunctional devices, especially for photovoltaics.

Preparation of highly oriented single crystal arrays of C8-BTBT by epitaxial growth on oriented isotactic polypropylene

Device arrays are fabricated with organic single crystals epitaxially grown on highly oriented iPP films by solvent vapor annealing.