Molecular Dynamics Simulations of Rare-Earth-Doped Nanoparticles in Silica Matrix: Drawing of a Preform to a Fiber

Abstract

By means of Molecular Dynamics simulations, rare-earth-doped nanoparticles are formed in situ through phase separation mechanism within MgO-SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> binary melt using a simple adaptive interatomic potential. The simulated preforms are doped with Eu <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> and Er <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> ions, and are then deformed into a fiber while glass flow effects (thermodynamical and rheological) leads to modifications of the nanoparticle's morphology. In this study, we highlight a rare-earth encapsulation in Mg-silicate nanoparticles more efficient for Er <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> ions than for Eu <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> ions. Moreover, the MgO concentration seems to converge toward a maximum value when the nanoparticles grow. Finally, preliminary results concerning the influence of the drawing parameters (temperature, elongation velocity) on the size's distribution and on the morphology of the nanoparticles are also presented.