Short-Range Structure of Yttrium Alumino-Silicate Glass for Cancer Radiotherapy: Car-Parrinello Molecular Dynamics Simulations.
ADVANCED ENGINEERING MATERIALS
We present Car-Parrinello molecular dynamics (CPMD) simulations of yttrium alumino-silicate (YAS) glass. Alumino-silicate glass microspheres are used as vectors of yttrium radioisotopes in cancer radiotherapy; understanding in detail how yttrium is bound within the glass network is important to control the unwanted release of radioactive yttrium in the bloodstream. Our simulations, focused on a specific composition relevant to practical applications, show that silicon and aluminum form a disordered glass network, where Si is mainly four-coordinated, whereas, Al is mainly four- and five-coordinated. Yttrium cations have a network-modifying role, disrupting the alumino-silicate network by breaking Si(Al)-O bonds and coordinating the resulting non-bridging oxygens (NBO). The local environment of yttrium in the glass turns out to be rather flexible: between five and eight oxygen atoms, with a marked predominance of NBO, are found coordinated to a central Y cation, leading to a corresponding broad and multimodal distribution of O-Y-O angles.
|Title:||Short-Range Structure of Yttrium Alumino-Silicate Glass for Cancer Radiotherapy: Car-Parrinello Molecular Dynamics Simulations|
|Keywords:||NEUTRON-DIFFRACTION, LANTHANUM, RADIATION, AL-27|
|UCL classification:||UCL > School of BEAMS > Faculty of Maths and Physical Sciences
UCL > School of BEAMS > Faculty of Maths and Physical Sciences > Chemistry
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