Magnetic phase diagram of the quantum spin chain compound SrCo$_{2}$V$_{2}$O$_{8}$: a single-crystal neutron diffraction study in magnetic field

TL;DR

This study maps the magnetic phase diagram of SrCo₂V₂O₈ using neutron diffraction, revealing multiple magnetic phase transitions under varying magnetic fields and temperatures, and highlighting unique spin states not seen in similar compounds.

Contribution

It provides the first detailed neutron diffraction-based phase diagram of SrCo₂V₂O₈ under high magnetic fields and low temperatures, uncovering novel magnetic states.

Findings

Identification of Néel, LSDW, and emergent AFM phases.

Observation of field-induced phase transitions at specific magnetic fields.

Detection of unique spin signatures absent in BaCo₂V₂O₈.

Abstract

We explore the spin states in the quantum spin chain compound SrCo$_{2}$V$_{2}$O$_{8}$ up to 14.9 T and down to 50 mK, using single-crystal neutron diffraction. Upon cooling in zero-field, antiferromagnetic (AFM) order of N\'eel type develops at $T_\mathrm{{N}}$ $\simeq$ 5.0 K. Applying an external magnetic field ($H$ $\parallel$ $c$-axis) destabilizes the N\'eel order, leading to an order-disorder transition when applying a field between $T_\mathrm{{N}}$ and $\sim$ 1.5 K. Below 1.5 K, we observe a N\'eel to longitudinal spin density wave (LSDW) order transition at 3.9 T, and a LSDW to emergent AFM order transition at 7.0 T. Our results also reveal several unique signatures for the states of the spins that are not present in the isostructural counterpart BaCo$_{2}$V$_{2}$O$_{8}$.