An investigation into silicon doping of MBE (100) GaAs

Abstract

A study of the silicon doping of MBE (molecular beam epitaxy) (100) GaAs is presented. The effects of the various growth parameters on the electrical properties of the layers have been investigated. In particular the influence of the As4:Ga flux ratio on the Si incorporation is considered. A model based on the site occupancy of the Si dopant and an As-induced defect Si-impurity complex is invoked to account for the observed electrical properties.

Growth of a dynamical correlation length in an aging superspin glass

“…The physico-chemical control of the dispersion (ionic strength, osmotic pressure, etc.) allows a fine tuning of the electrostatic repulsions (in regard to the dipolar interaction), leading to well dispersed nanoparticles, without the presence of large aggregates or chains.This sample is similar to a previously studied water based frozen ferrofluid [26] but with a lower volume fraction.…”

“…At low temperature, a transition towards a frustrated state of randomly interacting giant spins is observed, with slow dynamics and aging. These observed similarities with spin glasses [19][20][21][22][23][24][25][26][27] are at the origin of the term 'superspin glasses' which is now used to describe such materials [28]. Our present aim concerns this superspin glass transition and more precisely the extraction of a growing number of correlated superspins as the system ages.…”