Magnetic Phase Diagrams of Antiferromagnet DyB12 with Jahn-Teller Lattice Instability and Electron Phase Separation

TL;DR

This study explores the complex magnetic phases of DyB12, revealing how charge fluctuations and lattice instabilities influence its magnetic and transport properties, including phase diagrams and magnetoresistance patterns.

Contribution

The paper provides detailed magnetic phase diagrams and demonstrates the role of charge stripes and spin density waves in DyB12's magnetic behavior, highlighting new insights into its electronic instabilities.

Findings

Magnetic phase diagrams with multiple phases and boundaries were constructed.

Charge stripes suppress RKKY exchange, affecting magnetic interactions.

Magnetoresistance exhibits butterfly-type anisotropy linked to charge fluctuations.

Abstract

The origin of charge transport and magnetization anisotropy was studied in DyB12, an antiferromagnetic (AF) metal with Neel temperature TN = 16.3 K that exhibits both cooperative Jahn-Teller distortions of the fcc crystal structure and nanoscale electronic instabilities (dynamic charge stripes). Based on the results obtained the magnetic field (H) vs temperature (T) phase diagrams have been constructed. Moreover, from angle dependent magnetoresistance and magnetization measurements the butterfly-type patterns of the H-phi magnetic phase diagram in the (110) plane were created, which include a number of different magnetic phases separated from each other by radial and circular boundaries. Several positive and negative contributions to magnetoresistance were separated and analyzed, providing arguments in favor of the important role of the spin density wave 5d-component in the magnetic structure of AF state. We argue that charge fluctuations in stripes are responsible for the suppression of the Ruderman-Kittel-Kasuya-Yoshida (RKKY) indirect exchange between the nearest neighbored Dy3+ ions located along the same 110 directions, as these dynamic charge stripes produce the magnetic phase diversity and the butterfly-type anisotropy in DyB12.