Magnetic phase transition in V2O3 nanocrystals

TL;DR

This study investigates how the magnetic phase transition in V2O3 nanocrystals is suppressed and gradually occurs over a temperature range, contrasting with the sharp transition seen in bulk material.

Contribution

It demonstrates the synthesis of V2O3 nanocrystals with controlled sizes and reveals the suppressed and gradual magnetic transition at the nanoscale.

Findings

Small nanoparticles show suppressed transition temperatures.

High-temperature phase volume fraction declines gradually with decreasing temperature.

Transition behavior differs from bulk V2O3, showing a gradual change.

Abstract

V2O3 nanocrystals can be synthesized through hydrothermal reduction of VO(OH)2 using hydrazine as a reducing agent. Addition of different ligands to the reaction produces nanoparticles, nanorods and nanoplatelets of different sizes. Small nanoparticles synthesized in this manner show suppression of the magnetic phase transition to lower temperatures. Using muon spin relaxation spectroscopy and synchrotron x-ray diffraction, it is determined that the volume fraction of the high-temperature phase, characterized by a rhombohedral structure and paramagnetism, gradually declines with decreasing temperature, in contrast to the sharp transition observed in bulk V2O3.