Interdiffusion of lateral composition modulated (GaP)2/(InP)2 short-period superlattices with different encapsulants

Abstract

The interdiffusion of lateral composition modulated (GaP)2/(InP) 2 short-period superlattices (SPSs) is reported. The lateral composition modulation is achieved by the strain induced lateral layer ordering (SILO) process. A blueshift in the interband transition is observed by photoluminescence spectroscopy for capless and SiO 2 encapsulated annealed SPSs (800 °C, 5.5 h), while the intensity and wavelength of Si3N4 encapsulated annealed SPSs are only slightly perturbed. From transmission electron microscopy, capless annealed SPSs (800 °C, 5.5 h) retain their lateral composition modulation, however, the (001/2) satellite reflections disappear. For long anneal times (48 h), the interband transition corresponds to that of a In0.50Ga 0.50P alloy, suggesting the lateral composition modulation disappears. The observed lateral interdiffusion coefficient exceeds the vertical by a factor of ∼30, suggesting SPS interdiffusion is enhanced by native point defects.

Relationships between facial temperature changes, end‐exercise affect and during‐exercise changes in affect: A preliminary study

“…Because of its non-invasive nature, tympanic thermometry has been used as the most favoured measurement process during the last two decades. However, although researchers have assumed that tympanic temperature is a valid measure of body's core temperature (e.g., Sato et al, 1996), it has more recently been found that it best reflects brain temperature (e.g., Kirk, Rainey, Vail, & Childs, 2009;Newsham, Saunders, & Nordin, 2002). Due to the existence of automatic physiological mechanisms that cool the brain during hyperthermia (Cabanac, 1993), one problem with brain temperature is that it shows only little variability during physical exercise, thus making it hard to statistically demonstrate significant effects of temperature fluctuations on self-reported pleasure-displeasure.…”