What are metastable phases?
Metastable states of matter (also referred as metastates) range from melting solids (or freezing liquids), boiling liquids (or condensing gases) and sublimating solids to supercooled liquids or superheated liquid-gas mixtures.
Are metastable phases equilibrium phases?
The objects of condensed media physics are primarily equilibrium states of substances with metastable phases viewed as an exception, while the overwhelming majority of organic substances investigated in chemistry are metastable.
What is metastable phase diagram?
In particular, metastable phase diagrams will be used to describe phase selection in cast iron (Fe-C) and stainless steels (Fe-Ni-Cr), showing the effect of quenching rate on solidification products. The formation of metastable compounds will be reported in Fe-B and Ni-B systems.
What is a metastable equilibrium?
[¦med·ə′stā·bəl ‚ē·kwə′lib·rē·əm] (physics) A condition in which a system returns to equilibrium after small (but not large) displacements; it may be represented by a ball resting in a small depression on top of a hill. (physical chemistry)
What are the characteristics of a metastable phase?
Metastable state, in physics and chemistry, particular excited state of an atom, nucleus, or other system that has a longer lifetime than the ordinary excited states and that generally has a shorter lifetime than the lowest, often stable, energy state, called the ground state.
What is a metastable material?
Metastable materials, or materials that transform to another state over a long period of time, are ubiquitous in both nature and technology and often have superior properties. Chocolate, for example, is metastable, with a lower melting point and better texture than stable chocolate.
When is a reaction intermediate not a metastable state?
In regions where a particular state is not the most stable, it may still be metastable. Reaction intermediates are relatively short-lived, and are usually thermodynamically unstable rather than metastable. The IUPAC recommends referring to these as transient rather than metastable.
Which is a stable configuration of a metastable bond?
A metastable state of weaker bond (1), a transitional ‘saddle’ configuration (2) and a stable state of stronger bond (3). In physics, metastability is a stable state of a dynamical system other than the system’s state of least energy .
Are there any transitions from a metastable excited level?
Transitions from metastable excited levels are typically those forbidden by electric dipole selection rules. This means that any transitions from this level are relatively unlikely to occur. In a sense, an electron that happens to find itself in a metastable configuration is trapped there.
Which is the best description of a metastable state?
States of matter. Metastable states of matter (also referred as metastates) range from melting solids (or freezing liquids), boiling liquids (or condensing gases) and sublimating solids to supercooled liquids or superheated liquid-gas mixtures.