Publication

Structure analysis of beta dicalcium silicate via scanning transmission electron microscope (STEM)

Abstract

Beta-dicalcium silicate (beta-C2S), one of the main phases in Portland cement clinker, offers some promising overviews regarding CO2 and energy savings potential compared to alite. Understanding the crystalline structure and reactive sites on beta-C2S surface is critical to enable further optimization of its use. There is a lack of such studies available in the literature. Particularly, regarding the atomic structure and reactive oxygen species of beta-C2S are still blank. Herein, crystal information analysis, including atomic structure and active oxygen atoms of lab-scale synthesized beta-C2S was achieved by spherical aberration-corrected scanning transmission electron microscope (STEM). Detailed compositions and accurate element distributions of atomic layers were thus presented. Results show that a number of (0 0 1) twin crystal planes are present in the beta-C2S structure. The exact positions of Ca and Si columns in beta-C2S crystal lattice were obtained from STEM images, which is consistent with the visualization results. The hydration heat evolution of beta-C2S within 30 d was investigated by isothermal calorimetry, showing that beta-C2S was almost unhydrated for 28 d, only with a weakly exothermic activity in the early stage (1-2 h). Finally, visualization, simulation and experiment results of atomic structure analysis, as well as the hydration behavior of beta-C2S, have a significant contribution to the crystal structure foundation data base, which is beneficial to understanding the intrinsic relationship between beta-C2S hydration and its atomic structure.

About this result
This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.
Related concepts (35)
Crystal structure
In crystallography, crystal structure is a description of the ordered arrangement of atoms, ions, or molecules in a crystalline material. Ordered structures occur from the intrinsic nature of the constituent particles to form symmetric patterns that repeat along the principal directions of three-dimensional space in matter. The smallest group of particles in the material that constitutes this repeating pattern is the unit cell of the structure.
Crystal twinning
Crystal twinning occurs when two or more adjacent crystals of the same mineral are oriented so that they share some of the same crystal lattice points in a symmetrical manner. The result is an intergrowth of two separate crystals that are tightly bonded to each other. The surface along which the lattice points are shared in twinned crystals is called a composition surface or twin plane. Crystallographers classify twinned crystals by a number of twin laws. These twin laws are specific to the crystal structure.
X-ray crystallography
X-ray crystallography is the experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions. By measuring the angles and intensities of these diffracted beams, a crystallographer can produce a three-dimensional picture of the density of electrons within the crystal. From this electron density, the mean positions of the atoms in the crystal can be determined, as well as their chemical bonds, their crystallographic disorder, and various other information.
Show more
Related publications (54)

Concrete cancer : characterization of Alkali Silica Reaction early stage products by electron microscopy

Solène Anne-Lise Albinski

Concrete deterioration is a natural process, which has to be carefully monitored over a the service life of a structure. The Alkali-Silica Reaction (ASR) is a slow-process degradation, which devel-ops over decades and is therefore difficult to predict. Sin ...
EPFL2022

Experimental Analysis of Ductile Cutting Regime in Face Milling of Sintered Silicon Carbide

Lorenz Hagelüken

In this study, sintered silicon carbide is machined on a high-precision milling machine with a high-speed spindle, closed-loop linear drives and friction-free micro gap hydrostatics. A series of experiments was undertaken varying the relevant process param ...
2022

Holographic Convergent Electron Beam Diffraction (Cbed) Imaging Of Two-Dimensional Crystals

Tatiana Latychevskaia

Convergent beam electron diffraction (CBED) performed on two-dimensional (2D) materials recently emerged as a powerful tool to study structural and stacking defects, adsorbates, atomic 3D displacements in the layers, and the interlayer distances. The forma ...
WORLD SCIENTIFIC PUBL CO PTE LTD2021
Show more
Related MOOCs (21)
Cement Chemistry and Sustainable Cementitious Materials
Learn the basics of cement chemistry and laboratory best practices for assessment of its key properties.
Sorption and transport in cementitious materials
Learn how to study and improve the durability of cementitious materials.
Transmission Electron Microscopy for Materials Sciences
Learn about the fundamentals of transmission electron microscopy in materials sciences: you will be able to understand papers where TEM has been used and have the necessary theoretical basis for takin
Show more

Graph Chatbot

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.