Study of morphological and luminescent properties of HfO2 nanocrystals synthesized by precipitation method

• Grant number: 19/20121-3
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Effective date (Start): October 01, 2020
• Effective date (End): February 29, 2024
• Field of knowledge: Engineering - Electrical Engineering
• Principal Investigator: Sonia Hatsue Tatumi
• Grantee: Alvaro de Farias Soares
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated scholarship(s): 20/15562-8 - HfO2 luminescent properties and its dosimetry applications to ionizing radiation, BE.EP.DD

Abstract

Thermoluminescence (TL) ionizing radiation dosimetry has been used since 1940 due to the pioneering study of Garlick & Gibson (1948). Since then, research has been carried out in the area, and currently researchers suggest the use Optically Stimulated Luminescence (OSL) of Alumina for dosimetry. The relevance of this branch is because detector materials are used to monitor doses received by workers in Nuclear Medicine, diagnostic and research centers, educational institutions, nuclear power plants, i.e., places with sources or devices that emit radiation, as well as in the environmental area. Therefore, such monitoring is essential and mandatory for public health welfare, and accurate and rapid determination of these doses is necessary in all respects, so the development of research into new materials for this area is of great importance. In this respect, a material that has gained focus in the literature, due to its properties, the Hafnium Oxide (HfO2). However, there are no studies on literature for OSL decay curves for this material, either pure or doped; TL emissions present different results according to the proposed synthesis method and type of dopant; moreover, some point out the sensitivity of the material to Ultraviolet (UV) radiation, radiation whose exposure can occur naturally by solar radiation, and artificially, as a medical, in the treatment of diseases by phototherapy,and more recently there is a proposal to disinfect medical facilities in hospitals and ICUs with UVC irradiation. In this way, the project aims to synthesize nanocrystals of pure HfO2 and doped with Ag (silver), analyze its morphological and luminescent properties, the influence of heat treatment and doping, and its application as a radiation detector, including UV. (AU)