Local environment of Cs as a dopant in BaTiO3: a radioactive waste immobilization investigation by measuring hyperfine interactions using a nuclear technique.

• Grant number: 24/12795-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2024
• End date: September 30, 2025
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Artur Wilson Carbonari
• Grantee: Anna Clara Nicolini Gabriel
• Host Institution: Instituto de Pesquisas Energéticas e Nucleares (IPEN). Secretaria de Desenvolvimento Econômico (São Paulo - Estado). São Paulo , SP, Brazil

Abstract

The present project aims to investigate a metallic oxide with a perovskite structure of the BaTiO3 type and its doping by the Cs element, in order to analyze its instability when exposed to different doses of radiation. Different synthesis methods of this structure will be employed, namely solid-state synthesis and hydrothermal synthesis, and then compared to determine the one with the best applicability. Subsequently, doping will be performed by diffusing a solution containing a stable isotope of cesium. The analyses of the results will be conducted using X-ray diffraction (DRX), energy-dispersive X-ray spectroscopy (EDS), and perturbed angular correlation (PAC) gamma-gamma spectroscopy. In this context, PAC will be employed to perform experimental measurements on samples using 111In(111Cd) as the probe nucleus. Due to its nuclear nature, PAC spectroscopy offers high precision and efficiency in measuring local hyperfine fields on an atomic scale at any temperature, making it an ideal tool for investigating the atomic origins of structural phenomena. This includes exploring the influence of defects on the macroscopic properties of various materials or examining the local environment of metallic atoms within oxide structures. In this way, the relevance of perovskite in the context of radionuclide immobilization, particularly when doped with the cesium element, will be analyzed.