Large Magnetic-Field-Induced Strain at the Spin-Reorientation Transition in the A-Site Ordered Spinel Oxide LiFeCr4O8

TL;DR

This study demonstrates a significant magnetic-field-induced strain in LiFeCr4O8 at a specific temperature due to a spin-reorientation transition, highlighting strong spin-lattice coupling effects in localized magnets.

Contribution

It reveals a large magnetic-field-induced volume change associated with a spin-reorientation transition in a spinel oxide, emphasizing the role of phase coexistence and spin-lattice coupling.

Findings

Large volume increase (~500 ppm) at 9 T magnetic field.

The effect occurs around 30 K during a spin-reorientation transition.

Coexistence of ferrimagnetic and conical phases is crucial.

Abstract

Sintered samples of a spinel oxide LiFeCr4O8, where Cr3+ and Fe3+ ions have localized moments, were found to show a large magnetic-field-induced volume increase approaching 500 ppm by applying a magnetic field of 9 T. This large volume increase appeared only at around 30 K. At 30 K, a spin-reorientation transition from ferrimagnetic to conical order occurs, giving rise to this large volume increase. The coexistence of ferrimagnetic and conical phases at this transition was found to be important, suggesting that such a large magnetic-field-induced volume change can be realized at various magnetic transitions in localized magnets with strong spin-lattice coupling.