Übergangstemperatur

Übergangstemperatur, often translated as transition temperature, refers to a specific temperature at which a substance undergoes a change in its physical state or properties. This transition is typically a phase change, such as melting, boiling, or freezing, where the substance shifts from one phase (solid, liquid, or gas) to another. For example, the Übergangstemperatur for water at standard atmospheric pressure is 0 degrees Celsius (273.15 Kelvin) for freezing and melting, and 100 degrees Celsius (373.15 Kelvin) for boiling and condensation.

Beyond simple phase transitions, the term Übergangstemperatur can also describe the temperature at which a material exhibits a significant change in a particular characteristic. This is particularly relevant in materials science. For instance, superconductors have a critical Übergangstemperatur below which they lose all electrical resistance. Similarly, ferromagnetic materials experience a Curie temperature, which is a critical Übergangstemperatur where they lose their permanent magnetism and become paramagnetic. Amorphous solids, such as glass, do not have a sharp melting point but rather a glass transition temperature (Tg), which marks the temperature range where they transition from a rigid, glassy state to a more flexible, rubbery state. The precise value of the Übergangstemperatur is dependent on the substance and external conditions like pressure.