La conductivité électrique des couches microcristallines des métaux à conduction mixte (beryllium et plomb)

Microcrystalline continuous beryllium and lead films deposited by vacuum evaporation have a negative temperature coefficient of the resistance and anomalous values of the Hall and magnetoresistance constants. These anomalies are attributed to electrons thermically excited into the minima of the conduction band situated above the Fermi level.Les couches continues de béryllium et de plomb à très petits grains obtenues par évaporation sous vide présentent un coefficient de température de la résistance négatif, ainsi que des valeurs anormales de la constante de Hall et de la magnétorésistance. Ces anomalies sont attribuées aux électrons thermiquement excités qui se trouvent dans les minima de la bande de conduction situés au-dessus du niveau de Fermi

Tracking the physical aging of poly(ethylene oxide): A technical note

Physical aging of 2 types of PEO could be tracked by the combination of PALS, DSC, and SEM methods. After storing the samples at 40°C±2°C and 75%±5% RH, a decrease in the o-Ps lifetime values and an increase in the melting enthalpies as a function of storage time indicated a reorientation of the polymer chains. The limitations of monitoring enthalpy relaxation confirm the importance of methods that track volume relaxation, such as PALS. Structural changes could be observed even after a short storage time (4 weeks), which highlights the effect of further investigations of the influence of physical aging on the properties of PEO-containing dosage forms