Magnetic glasses and structural glasses: devitrification and a reentrant transition under CHUF protocol

A recent paper from Raveau's group asserts that the specially designed CHUF measurement protocol serves to bring out a special feature of the magnetic glass state. This protocol, enunciated and applied in our publications since over three years, allows establishing phase coexistence through macroscopic measurements and distinguishing the metastable and stable phases (amongst the coexisting phase fractions across a first order magnetic transition) of a glass-like arrested state. In view of the recent report of the vitrification of monoatomic germanium under pressure, we discuss the applicability of an analogous CHUP protocol for states across an arrested first order structural transition, and specifically in establishing whether the vitrification was partial or complete.