Development of Wideband Excitation Strategies for Quadrupolar Nuclei: Application to Structural Studies of Glasses

• Grant number: 25/06921-8
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: July 01, 2025
• End date: June 30, 2026
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Hellmut Eckert
• Grantee: Rafaella Bartz Pena
• Supervisor: Michael Ryan Hansen
• Host Institution: Instituto de Física de São Carlos (IFSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Institution abroad: University of Munster, Germany
• Associated to the scholarship: 23/17069-5 - The Structural Role of Transition Metal Oxides in Borate and Phosphate Glasses Studied by Dipolar Magnetic Resonance Techniques of Quadrupolar Nuclei, BP.PD

Abstract

Nuclear magnetic resonance (NMR) offers element-selective, inherently quantitative and locally selective capabilities, which, combined with the versatile pulse-selective methods, can probe the short- and intermediate-range orders in a broad range of materials, including those in the vitreous state. The query into the structural details comprising transition metal ions incorporation in glasses can provide further insights into the structure-property correlations. However, the quadrupolar nature of the corresponding nuclei tends to present low-resolution and sensitivity challenges in standard solid-state NMR characterizations. In this BEPE research project, a great deal of effort is devoted to the simulation-based development of optimized wideband excitation/refocusing methods and protocols for efficient excitation of quadrupolar nuclei with spin-5/2 and spin-7/2, such as 47Ti, 49Ti, and 95Mo. These advanced methods are subsequently applied to studying titanium- and molybdenum-containing phosphate glasses, serving as benchmark candidates for prospective extrapolation of such NMR pulse-sequence routines towards other quadrupolar nuclei relevant to glass science.