Single crystal

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

Naphtho[2,1-b:6,5-b']difuran: a versatile motif available for solution-processed single-crystal organic field-effect transistors with high hole mobility.

Abstract: We here report naphtho[2,1-b:6,5-b′]difuran derivatives as new p-type semiconductors that achieve hole mobilities of up to 3.6 cm2 V–1 s–1 along with high Ion/Ioff ratios in solution-processed single-crystal organic field-effect transistors. These features originate from the dense crystal packing and the resulting large intermolecular π-orbital overlap as well as from the small reorganization energy, all of which originate from the small radius of an oxygen atom.

Tailoring the structural, morphological, optical and dielectric properties of lead iodide through Nd 3+ doping

Abstract: Hexagonal single crystal nanosheets of Nd3+ doped PbI2 were effortlessly synthesized via microwave-assisted technique under a power of 700 W and in a duration of 15 minutes with a homogeneous morphology. X-ray diffraction, energy dispersive X-ray spectroscope, scanning electron microscope, FT-Raman, UV-Visible, photoluminescence and dielectric measurement were employed to study the product. High purity, single phase and presence of Nd3+ doping was confirmed. SEM study confirm the formation of nanorods and single crystal nanosheets of very few nanometers in size. Robust vibrational analysis has been carried out and the observed bands are assigned to the vibration modes of E21, A11, A12, 2E21 and 2E11, respectively. These bands are red-shifted when compare to the corresponding bulk values which indicate relaxed nanostructure formation and occurrence of confinement effect. The thickness of the synthesized single crystal nanosheets are found to be in the range of ~20 to 30 nm. The energy band gap was calculated and found to be 3.35, 3.34, 3.42 and 3.39 eV for pure, 1, 3 and 5% Nd3+ doped lead iodide, respectively. The clear blue luminescence has been observed at 440 nm and 466 nm when excited at 250 nm and 280 nm respectively. Dielectric and ac electrical conductivity was also measured and discussed.

Fracture anisotropy in silicon single crystal

Abstract: In this study the effect of crystallographic orientation on fracture toughness and the fracture path of silicon single crystal was investigated Vickers microhardness indentation was used to introduce cracks along various crystallographic orientations on the (110), (001), and (111) planes The fracture toughness variation was found to follow the symmetry of the indentation axis with no distinct correlation with the elastic constants The observations made suggest that the inclination angle of cleavage planes relative to the indent plane affects the fracture path and toughness significantly Prestraining decreased the hardness and improved the toughness without a modification of fracture path

Amorphization of SiC under ion and neutron irradiation

Abstract: This paper presents results on the microstructure and physical properties of SiC amorphized by both ion and neutron irradiation. Specifically, 0.56 MeV Si ions have been implanted in single crystal 6H–SiC from ambient through >200°C and the critical threshold for amorphization was measured as a function of the irradiation temperature. From a high resolution transmission electron microscopy (HRTEM) study of the crystalline to amorphous transition region in these materials, elongated pockets of amorphous material oriented parallel to the free surface are observed. Single crystal 6H–SiC and hot pressed and sintered 6H and 3C SiC were neutron irradiated at approximately 70°C to a dose of ∼2.56 dpa causing complete amorphization. Property changes resulting from the crystal to amorphous transition in SiC include a density decrease of 10.8%, a hardness decrease from 38.7 to 21.0 GPa, and a decrease in elastic modulus from 528 to 292 GPa. Recrystallization of the amorphized, single crystal 6H–SiC appears to occur in two stages. In the temperature range of ∼800–1000°C, crystallites nucleate and slowly grow. In the temperature range of 1125–1150°C spontaneous nucleation and rapid growth of crystallites occur. It is further noted that amorphized 6H (alpha) SiC recrystallizes to highly faulted fcc (beta) SiC.