Non-equilibrium dynamics in geometrically frustrated spin glass Bi$_2$Fe$_3$GaO$_9$ with a Cairo lattice

TL;DR

This study investigates the non-equilibrium relaxation and memory effects in the geometrically frustrated spin glass Bi$_2$Fe$_3$GaO$_9$ with a Cairo lattice, revealing classical spin glass-like behavior and potential for neutron scattering studies.

Contribution

It provides new insights into the relaxation dynamics and memory effects in a Cairo lattice-based spin glass, highlighting its similarities to classical spin glasses.

Findings

Relaxation time follows Arrhenius law with temperature.

Memory effects resemble classical spin glasses.

Relaxation time remains constant with magnetic field variations.

Abstract

We have explored the relaxation process of the spin glass phase in Bi$_2$Fe$_3$GaO$_9$, a geometrically frustrated magnet with a unique structure consisting of pentagonal building blocks known as the Cairo lattice. Using dc magnetization measurements on single crystals, we estimate the relaxation time across various temperatures and fields. Our results indicate that the relaxation time of Bi$_2$Fe$_3$GaO$_9$ follows the Arrhenius law as a function of temperature but remains relatively constant as the applied magnetic field varies. Further, through a carefully designed protocol, we observe significant rejuvenation and memory effects. Remarkably, the memory effects in Bi$_2$Fe$_3$GaO$_9$ are found to be more similar to those observed in classical spin glasses rather than in spin jamming systems, both in terms of the magnitude of the memory effect and the value of the exponent that describes the relaxation behavior. Our findings suggest that Bi$_2$Fe$_3$GaO$_9$ provides an excellent platform for investigating the time-dependent evolution of underlying magnetism using neutron scattering, paving the way for future research.