Low temperature heat capacity of phononic crystal membranes

Low-Temperature Coherent Thermal Conduction in Thin Phononic Crystal Membranes

In recent years, the idea of controlling phonon thermal transport coherently using phononic crystals has been introduced. Here, we extend our previous numerical studies of ballistic low-temperature heat transport in two-dimensional hole-array phononic crystals, and concentrate on the effect of the lattice periodicity. We find that thermal conductance can be either enhanced or reduced by large f...

Low-temperature excess heat capacity in fresnoite glass and crystal

The effect of thermal annealing on low-temperature excess heat capacity was investigated in fresnoite (Ba2TiSi2O8) glass. The amplitudes of the excess heat capacity decreased, and their positions shifted to a higher temperature by relaxation or crystallization. In particular, we revealed that the change in the excess heat capacity during transition from the glassy state to the crystalline state...

Low-temperature Normal-state Heat Capacity of Tungsten

Low Temperature Heat Capacity and Thermodynamic Properties of Zinc Ferrite*

The heat capacity of zinc ferrite (ZnFe,O,) has been determined over the range 5 to 350°K. Molal values of C~,S’, and HO-H,O computed from the thermal data are 32,99&t-0.03 cal/deg., 36.01 f0.03 cal/deg., and 18,00&0.02 Cal, respectively, at 298,lS”K. A co-operative thermal anomaly associated with antiferromagnetic ordering occurs at 9.5” and extends toward higher temperatures probably as a con...

Transformation of sound by a phononic crystal

Several noise barriers made of phononic crystals (i.e. manmade composite materials with a periodic structure) have been designed over the last decade. The periodic structure of phononic crystal avoids sound propagation in a defined frequency range called Bragg band gap (i.e. waves are evanescent). This study aims at quantifying the perceptual impact of a noise barrier based on a phononic crysta...