Structural disorder in new geometrically frustrated magnets candidates of Quantum Spin Liquid

• Grant number: 23/12679-0
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: January 01, 2024
• End date: February 29, 2028
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Rafael Sá de Freitas
• Grantee: Pedro Lucas Oliveira Silva
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated scholarship(s): 25/01609-6 - Characterizing thermomagnetic properties and crystal field excitations in rare-earth disordered pyrochlores candidates of strongly correlated ground states, BE.EP.DD

Abstract

In this project, we will investigate several materials from the A2B2O7 family (with magnetically frustrated structures such as pyrochlore or fluorite), where A is a 3+ rare-earth ion and B is a 4+ transition metal (Zr, Ti, Hf...). Combining the effects of structural disorder and magnetic frustration, this class of materials has piqued the interest of the international scientific community due to its extensive and diverse set of exotic behaviors at low temperatures. In particular, the proof of the existence of the liquid state of quantum spin emerges as one of the biggest experimental paradigms to be overcome in the field of magnetic materials, and some candidates for this phase are members of the A2B2O7 family. Hafnates A2Hf2O7 (A=La, Eu, Gd, Tb, Dy, Ho, Er), Pr2(Sn2-xPrx)O7 and Pr2(Zr2-xPrx)O7, and Ho2Zr2O7 will be synthesized using the Solid-State reaction technique and an alternative chemical route, the sol-gel technique. The study of physical properties will be carried out using various techniques, including X-ray diffraction, X-ray absorption, electron microscopy, Raman scattering, magnetization, AC magnetic susceptibility, specific heat, and neutron scattering.