## λ-transition (lambda-transition)

https://doi.org/10.1351/goldbook.T03420
A @S05531@ or @H02822@, in which the @H02753@ shows either a discontinuity (second-order) or a vertex (higher-order) at the transition temperature. Example: The transition at $$846\ \text{K}$$, accompanied by a finite change in @S05800@ at constant pressure $$C_{p}$$, of the low-temperature polymorph of quartz to the high-temperature polymorph.
Source:
PAC, 1994, 66, 577. (Definitions of terms relating to phase transitions of the solid state (IUPAC Recommendations 1994)) on page 584 [Terms] [Paper]