“Millikelvin‐Stabilized Cell” for the Precise Study of Phase Transitions

A simple “millikelvin‐stabilized cell” of a small size having a high degree of temperature stability and a resolution better than 1 mK has been developed to study precisely phase transitions in solids, passing through the transition point very slowly on both heating and cooling. It has multiple thermal shields that are most effective to achieve excellent innermost temperature stability. The temperature is regulated by a kind of predictive control using a personal computer. The “cell” enables us to make not only heat flux measurement but also X‐ray diffraction with heat anomaly sensing, dielectric constant, displacement current and dilatometric measurements simultaneously with endothermic or exothermic heat measurements. Results of its application to the perovskite‐type compounds are shown.