Single crystal

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

Guest-induced asymmetry in a metal-organic porous solid with reversible single-crystal-to-single-crystal structural transformation.

Abstract: A metal−organic honeycomb-like 2D pillared-bilayer open framework has been constructed which shows dynamic sponge-like single-crystal-to-single-crystal transformation upon dehydration and rehydration. The dehydrated acentric nonporous phase transformed to the porous centric phase with the selective adsorbate concomitant with the structural transformation correlated with the single-crystal structure determination.

Laser-Ablation Growth and Optical Properties of Wide and Long Single-Crystal SnO2 Ribbons

Abstract: Wide and long ribbons of single-crystalline SnO2 have been achieved via laser ablation of a SnO2 target. Transmission electron microscopy (TEM) shows the as-grown SnO2 ribbons are structurally perfect and uniform, with widths of 300-500 nm, thicknesses of 30-50 nm (width-to-thickness ratio of ∼ 10), and lengths ranging from several hundreds of micrometers to the order of millimeters. X-ray diffraction (XRD) pattern and energy-dispersive X-ray spectroscopy (EDS) spectral analysis indicate that the ribbons have the phase structure and chemical composition of the rutile form of SnO2. Selected-area electron diffraction (SAED) patterns and high-resolution TEM images reveal that the ribbons are single crystals and grow along the [100] crystal direction. Photoluminescence measurements show that the synthesized SnO2 ribbons have one strong emission band at ∼ 605 nm and a red-shift of ∼ 30 nm, as compared to standard SnO2 powder, which may be attributed to crystal defects and residual strains accommodated during the growth of the ribbons.

The crystal structure and phase transitions of the magnetic shape memory compound Ni2MnGa

Abstract: High resolution neutron powder diffraction and single crystal measurements on the ferromagnetic shape memory compound Ni2MnGa have been carried out. They enabled the sequence of transformations which take place when the unstressed, stoichiometric compound is cooled from 400 to 20 K to be established. For the first time the crystallographic structure of each of the phases which occur has been determined. At 400 K the compound has the cubic L21 structure, and orders ferromagnetically at TC ≈ 365 K. On cooling below ~ 260 K a super-structure, characterized by tripling of the repeat in one of the 110cubic directions, forms. This phase, known as the pre-martensitic phase, persists down to the structural phase transition at TM ≈ 200 K and can be described by an orthorhombic unit cell with lattice parameters aortho = 1/√2acubic, bortho = 3/√2acubic, cortho = acubic and space group Pnnm. Below TM the compound has a related orthorhombic super-cell with bortho ≈ 7/√2acubic, which can be described within the same space group. The new modulation appears abruptly at TM and remains stable down to at least 20 K.