Dimensionality-driven spin-flop transition in quasi-one-dimensional PrBa2Cu4O8

TL;DR

This study reveals a spin-flop transition in PrBa2Cu4O8 linked to a dimensional crossover in the CuO chains, driven by changes in RKKY interactions affecting magnetic ordering.

Contribution

It demonstrates a direct connection between magnetic spin reorientation and electronic dimensionality changes in a quasi-one-dimensional cuprate.

Findings

Identification of a spin-flop transition at 17 K

Correlation between spin-flop and dimensional crossover

Evidence of RKKY interaction influence on magnetic behavior

Abstract

In the quasi-one-dimensional cuprate PrBa$_2$Cu$_4$O$_8$, the Pr cations order antiferromagnetically at 17 K in zero field. Through a combination of magnetic susceptibility, torque magnetometry, specific heat and interchain transport measurements, the anisotropic temperature-magnetic field phase diagram associated with this ordering has been mapped out. A low-temperature spin-flop transition in the Pr sub-lattice is found to occur at the same magnetic field strength and orientation as a dimensional crossover in the ground state of the metallic CuO chains. This coincidence suggests that the spin reorientation is driven by a change in the anisotropic Rudermann-Kittel-Kasuya-Yosida (RKKY) interaction induced by a corresponding change in effective dimensionality of the conduction electrons.