Related Experiment Video
Updated: Jul 3, 2026
12:37
Phase Diagram Characterization Using Magnetic Beads as Liquid Carriers
Published on: September 4, 2015
How electron localization function quantifies and pictures chemical changes in a solid: the B3-->B1 pressure induced
J Contreras-García1, A Martín Pendás, J M Recio
1Departamento de Química Física y Analítica, Universidad de Oviedo, E-33006 Oviedo, Spain.
The Journal of Physical Chemistry. B
|July 19, 2008
Summary
The study of beryllium oxide (BeO) reveals how electron localization function (ELF) analysis tracks chemical bonding changes during the zinc blende to rock salt phase transformation. This transition involves bond emergence and evolution, impacting coordination and material properties.
Area of Science:
- Solid-state chemistry
- Materials science
- Computational chemistry
Background:
- Phase transitions in solids are crucial for understanding material properties.
- Electron localization function (ELF) analysis offers insights into chemical bonding.
- Beryllium oxide (BeO) exhibits a pressure-induced phase transition.
Purpose of the Study:
- To analyze the zinc blende (B3) to rock salt (B1) phase transformation in BeO.
- To characterize changes in chemical bonding during this transition using ELF topology.
- To correlate bonding evolution with changes in coordination, volume, and bulk modulus.
Main Methods:
- Topological analysis of the electron localization function (ELF).
- Investigating the BeO phase transition from 4-fold to 6-fold coordination.
- Qualitative and quantitative tracing of bonding changes to the oxygen valence shell.
Main Results:
- The transformation initiates with the sudden formation of new Be-O bonds, signaling the rock salt structure.
- These new bonds gradually evolve to form the high-pressure phase's bonding network.
- Increased coordination, volume collapse, and enhanced bulk modulus are linked to oxygen's valence shell.
- ELF analysis indicates greater bond polarity in the B3 than B1 structure, but no fundamental change in interaction nature.
Conclusions:
- The BeO phase transition is a two-step process involving bond emergence and evolution.
- ELF topology effectively characterizes the chemical bonding changes during the transformation.
- Despite polarity shifts, the fundamental nature of crystal interactions remains largely unchanged post-transition.
More Related Videos
Related Concept Videos
02:31Phase Transitions
Whether solid, liquid, or gas, a substance's state depends on the order and arrangement of its particles (atoms, molecules, or ions). Particles in the solid pack closely together, generally in a pattern. The particles vibrate about their fixed positions but do not move or squeeze past their neighbors. In liquids, although the particles are closely spaced, they are randomly arranged. The position of the particles are not fixed—that is, they are free to move past their neighbors to occupy...
01:21Phase Transitions
A phase transition is the process in which a substance changes from one state of matter to another, like from a solid to a liquid, liquid to gas, or vice versa, at a specific temperature and under given pressure conditions. This change is spontaneous and is affected by alterations in temperature and pressure. These parameters impact the strength of the forces between molecules (intermolecular forces) in the substance.During a phase transition, both the initial and final phases of the substance...
01:19Phase Diagram
The phase of a given substance depends on the pressure and temperature. Thus, plots of pressure versus temperature showing the phase in each region provide considerable insights into the thermal properties of substances. Such plots are known as phase diagrams. For instance, in the phase diagram for water (Figure 1), the solid curve boundaries between the phases indicate phase transitions (i.e., temperatures and pressures at which the phases coexist).
01:24Phase Diagram
A phase diagram is a graphical representation of the physical states of a substance under different conditions of temperature and pressure. It shows the boundaries between solid, liquid, and gas phases and the conditions at which these phases coexist in equilibrium. An area in a phase diagram represents a single phase, whereas lines or phase boundaries represent the equilibrium between two phases.In the phase diagram of water, the boundary line between the solid and liquid states illustrates...
02:39Phase Transitions: Melting and Freezing
Heating a crystalline solid increases the average energy of its atoms, molecules, or ions, and the solid gets hotter. At some point, the added energy becomes large enough to partially overcome the forces holding the molecules or ions of the solid in their fixed positions, and the solid begins the process of transitioning to the liquid state or melting. At this point, the temperature of the solid stops rising, despite the continual input of heat, and it remains constant until all of the solid is...
00:59States of Matter and Phase Changes
The internal energy of a substance—the total kinetic energy of all its molecules and the potential energy of their associated forces—depends on the strength of the intermolecular forces in the condensed phases and the pressure exerted on the substance. The internal energy of a substance is the highest in the gaseous state, the lowest in the solid state, and intermediate in the liquid state. Phase transitions are caused by changes in physical conditions, such as temperature and pressure, that...