Single crystal

About: Single crystal is a research topic. Over the lifetime, 59617 publications have been published within this topic receiving 870828 citations.

Alpha-irradiation damage in CeO2, UO2 and PuO2

Abstract: Sintered pellets of CeO2 and UO2, as well as PuO2 powder, have been irradiated with alpha particles emitted from an effectively semi-infinite 238PuO2 source. The lattice parameters of all three materials increased with dose, Dα, according to the expression δa/a0 = A[1—exp(—BDα)], in agreement with a previously developed model. The recovery behavior of the lattice defects has been studied by isochronal annealing. Two recovery stages were observed in the temperature range between 50 and 1000°C for each material, and the activation energies were estimated based on previous single crystal studies. Comparisons with self-damage from alpha decay are made, and the behavior of the lattice defects is discussed.

α,ω-Dihexylquaterthiophene: A Second Thin Film Single-Crystal Organic Semiconductor

Abstract: The thin film structure and hole mobility of 5,5‘‘‘-dihexylquaterthiophene are reported. Films sublimed onto Si/SiO2 or carbon grids held at 30−100 °C are single-crystal-like over tens of micrometers as shown by electron diffraction. The orientation has the long axis of the quaterthiophene core nearly perpendicular to the substrate. The mobility ranges from 0.05 to 0.23 cm2/Vs, depending on the deposition temperature, much higher than would be expected based on earlier thiophene oligomer data.

Titanium diffusion into LiNbO3 as a function of stoichiometry

Abstract: The diffusivity of Ti into LiNbO3 has been measured as a function of crystal orientation and Li/Nb ratio in the temperature range 980–1112 °C. The Li/Nb ratios of single crystal samples were adjusted by vapor phase equilibration with fixed Li2O activities. No anisotropy of diffusivity with crystal orientation could be detected. The diffusion constants for Ti in LiNbO3 decrease with increasing Li2O content. At 1050 °C, the values decrease from 2.60×10−12 cm2/s at the Li2O‐deficient phase boundary (48.1 mol % Li2O) to 1.06×10−12 cm2/s at the congruently melting composition at (48.6 mol % Li2O) to 0.4×10−12 cm2/s at the Li2O‐rich phase boundary (50.0 mol % Li2O). It is suggested that enhanced lateral diffusion observed for stripe geometry Ti sources results from increased diffusivity in a surface layer formed by Li2O outdiffusion.

A single crystal of YAG-new fast scintillator in SEM

Abstract: This letter presents basic results obtained with a single crystal of YAG:Ce3+ of 25 mm diameter and 60 mm high from which scintillators of arbitrary shape and size can be ground. Single crystals of this size were prepared by growth from a melt in an atmosphere comprising a special gas mixture and at well correlated crystal growth rates and solid-liquid interface temperature gradients. They contain about 1% of Ce3+ acting as the activator in the garnet crystal lattice.

High-performance dinaphtho-thieno-thiophene single crystal field-effect transistors

Abstract: We fabricated high-performance single crystal organic field-effect transistors (SC-OFETs) based on dinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]-thiophene (DNTT). Among various device geometries and contact types, best performance is obtained for a lamination-type SC-OFET composed of a Cytop-treated SiO2 gate dielectric and top-contact gold/tetrathiafulvalene-tetracyanoquinodimethane electrodes, which results in hysteresis-free device characteristics with optimum mobility of 8.3 cm2/V s and an on/off ratio of >108. The achieved performance is promising for use of the air-stable DNTT in future studies of intrinsic properties of molecular crystals.