Equilibrium and non-equilibrium transitions studied by adiabatic calorimetry

The principle and recent technical development of adiabatic low temperature calorimetry are described with experimental results taken mostly from the authors' laboratory. Topics on the equilibrium and quasi-equilibrium heat c apacities include the separation of the Schottky heat capacity from the exp erimental data on bromo-hydroxyphenalenone and non-Debye excess heat capaci ty of a glassy hydrocarbon. Relaxation of glassy crystals of rubidium cyani de and C-60 and stabilization of a supercooled phase of methylammonium hexa chlorotellurate are discussed. A unique adiabatic calorimeter of top-loadin g construction recently completed in the authors' laboratory is described a long with an experimental result on a glassy liquid prepared at a cooling r ate 100 times greater than was possible with a calorimeter of the conventio nal design. (C) 1999 Elsevier Science B.V. All rights reserved.