Synthesis, Optical, and Magnetic Properties of Ba$_2$Ni$_3$F$_{10}$ Nanowires

TL;DR

This study reports the synthesis of pure Ba₂Ni₃F₁₀ nanowires via a hydrothermal method, revealing their optical emission properties and weak ferromagnetism attributed to surface strain and core-shell magnetic structure.

Contribution

It introduces a low-temperature hydrothermal synthesis method for Ba₂Ni₃F₁₀ nanowires and elucidates their optical and magnetic properties with first-principles calculations.

Findings

Nanowires exhibit three emission bands at 360, 530, and 700 nm.

Weak ferromagnetism observed below 60 K with hysteresis loops.

Exchange bias with a blocking temperature of 55 K was identified.

Abstract

A low temperature hydrothermal route has been developed, and pure phase Ba$_2$Ni$_3$F$_{10}$ nanowires have been successfully prepared under the optimized conditions. Under the 325 nm excitation, the Ba$_2$Ni$_3$F$_{10}$ nanowires exhibit three emission bands with peak positions locating at 360 nm, 530 nm, and 700 nm, respectively. Combined with the first-principles calculations, the photoluminescence property can be explained by the electron transitions between the t2g and eg orbitals. Clear hysteresis loops observed below the temperature of 60 K demonstrates the weak ferromagnetism in Ba$_2$Ni$_3$F$_{10}$ nanowires, which has been attributed to the surface strain of nanowires. Exchange bias with blocking temperature of 55 K has been observed, which originates from the magnetization pinning under the cooling field due to antiferromagnetic core/weak ferromagnetic shell structure of Ba2Ni3F10 nanowires.