Related Experiment Video
Updated: Jan 6, 2026
10:08
Phase Behavior of Charged Vesicles Under Symmetric and Asymmetric Solution Conditions Monitored with Fluorescence Microscopy
Published on: October 24, 2017
9.6K
FCC ↔ BCC Phase Transitions in Convex and Concave Hard Particle Systems.
Duanduan Wan1, Chrisy Xiyu Du, Greg van Anders2
1School of Physics and Technology , Wuhan University , Wuhan 430072 , China.
The Journal of Physical Chemistry. B
|October 2, 2019
Summary
Researchers explored solid-solid transitions between face-centered cubic (FCC) and body-centered cubic (BCC) structures. Particle shape manipulation was used to investigate transition pathways, revealing that these transitions are primarily first-order, regardless of particle shape.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Crystallography
Background:
- Solid-solid transitions, such as between face-centered cubic (FCC) and body-centered cubic (BCC) structures, are fundamental in nature and critical for technological applications.
- The existence of multiple transition pathways complicates the understanding and control of these transformations.
- Symmetry allows for continuous or discontinuous (first-order) pathways between FCC and BCC structures, but selecting between them remains an open question.
Purpose of the Study:
- To investigate the influence of particle shape on the pathways of FCC ↔ BCC solid-solid transitions.
- To determine whether specific particle geometries can select or favor particular transition mechanisms.
- To elucidate the nature (continuous vs. first-order) of FCC ↔ BCC transitions induced by particle shape manipulation.
Main Methods:
- Utilizing systems with malleable particle valence to induce FCC ↔ BCC transitions.
- Employing particle shape engineering (both convex and concave) as a means to control and study transition mechanisms.
- Analyzing the resulting crystal structures and transition characteristics.
Main Results:
- Particle shape modification can influence the presence of metastable hexagonal close-packed (HCP) stacking faults.
- Despite variations in particle shape, all investigated transitions between FCC and BCC structures were found to be first-order.
- The study demonstrates that particle shape does not enable the selection of continuous transition pathways over first-order ones.
Conclusions:
- The nature of FCC ↔ BCC solid-solid transitions is predominantly first-order, irrespective of particle geometry.
- While particle shape can affect intermediate structures like stacking faults, it does not fundamentally alter the transition mechanism to favor continuous pathways.
- This finding has implications for designing materials with predictable solid-state transformations.
Related Concept Videos
02:39Phase Transitions: Melting and Freezing
14.5K
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...
14.5K
02:31Phase Transitions
22.2K
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...
22.2K
02:33Phase Transitions: Sublimation and Deposition
19.5K
Some solids can transition directly into the gaseous state, bypassing the liquid state, via a process known as sublimation. At room temperature and standard pressure, a piece of dry ice (solid CO2) sublimes, appearing to gradually disappear without ever forming any liquid. Snow and ice sublimate at temperatures below the melting point of water, a slow process that may be accelerated by winds and the reduced atmospheric pressures at high altitudes. When solid iodine is warmed, the solid sublimes...
19.5K
02:39Phase Transitions: Vaporization and Condensation
20.4K
The physical form of a substance changes on changing its temperature. For example, raising the temperature of a liquid causes the liquid to vaporize (convert into vapor). The process is called vaporization—a surface phenomenon. Vaporization occurs when the thermal motion of the molecules overcome the intermolecular forces, and the molecules (at the surface) escape into the gaseous state. When a liquid vaporizes in a closed container, gas molecules cannot escape. As these gas phase molecules...
20.4K
02:33Lattice Centering and Coordination Number
11.3K
The structure of a crystalline solid, whether a metal or not, is best described by considering its simplest repeating unit, which is referred to as its unit cell. The unit cell consists of lattice points that represent the locations of atoms or ions. The entire structure then consists of this unit cell repeating in three dimensions. The three different types of unit cells present in the cubic lattice are illustrated in Figure 1.
Types of Unit Cells
Imagine taking a large number of identical...
Types of Unit Cells
Imagine taking a large number of identical...
11.3K
01:23Equilibrium Conditions for a Particle
2.1K
When an object is in equilibrium, it is either at rest or moving with a constant velocity. There are two types of equilibrium: static and dynamic. Static equilibrium occurs when an object is at rest, while dynamic equilibrium occurs when an object is moving with a constant velocity. In both cases, there must be a balance of forces acting on the object.
To understand the concept of equilibrium, let us first consider the forces acting on an object. When different forces act on an object, they can...
To understand the concept of equilibrium, let us first consider the forces acting on an object. When different forces act on an object, they can...
2.1K