In contrast to viscosity, thermal expansion and heat capacity of amorphous materials show a relatively sudden change at the glass transition temperature which enables accurate detection using differential scanning calorimetry measurements.
32.
Amorphous materials do not have a eutectic point, but they do have a critical point, below which the product must be maintained to prevent melt-back or collapse during primary and secondary drying.
33.
In terms of chemistry, vitrification is characteristic for amorphous materials or disordered systems and occurs when bonding between elementary particles ( atoms, molecules, forming blocks ) becomes higher than a certain threshold value.
34.
Because of that amorphous materials have a characteristic threshold temperature termed glass transition temperature ( T g ) : below T g amorphous materials are glassy whereas above T g they are molten.
35.
When the temperature is higher than the glass transition temperature,, the activation energy of viscosity is low because amorphous materials are melted and have most of their joining bonds broken, which facilitates flow.
36.
In condensed matter physics, Adler made significant contributions to the understanding of transition-metal oxides, the electronic properties of low-mobility materials, transport phenomena in amorphous materials, metal-insulator transitions, and electronic defects in amorphous semiconductors.
37.
Because of that amorphous materials have a characteristic threshold temperature termed glass transition temperature ( T g ) : below T g amorphous materials are glassy whereas above T g they are molten.
38.
In amorphous materials such as polymers, amorphous ceramics ( glass ), and amorphous metals, the lack of long range order leads to yielding via mechanisms such as brittle fracture, crazing, and shear band formation.
39.
When the temperature is less than the glass transition temperature,, the activation energy of viscosity is high because the amorphous materials are in the glassy state and most of their joining bonds are intact.
40.
Perfect crystals never occur in practice; imperfections, and even entire amorphous material inclusions, can and do simply get " frozen in " at low temperatures, so transitions to more stable states do not occur.
