# Effects of B2O3 on the Growth, Structural, and Magneto-Optical Properties of Yttrium Iron Garnet Single-Crystal Fibers

## TL;DR

This study shows that adding B2O3 during the growth of YIG single-crystal fibers improves fabrication efficiency and enhances their structural and magneto-optical properties.

## Contribution

The novel use of B2O3 in LHPG growth improves YIG fiber quality and scalability for photonic and sensing applications.

## Key findings

- B2O3 lowers growth temperatures and improves fiber fabrication efficiency.
- B2O3-assisted fibers show increased saturation magnetization and better [111] crystal alignment.
- Faraday rotation measurements confirm improved phase purity and crystallographic quality in B2O3-assisted samples.

## Abstract

This study explores the fabrication of yttrium iron garnet
(YIG)
single crystal fibers using the laser heated pedestal growth (LHPG)
method with the experimental addition of B2O3. The incorporation of B2O3 facilitates the
fiber fabrication process by lowering the required growth temperatures
and likely modifying melt viscosity behavior, consistent with the
established fluxing behavior of B2O3 and the
comparative viscosity trend observed in the TMA–VFT analysis,
thereby improving process efficiency while maintaining fiber quality.
Structural characterization using EBSD and SC-XRD reveals a transition
from polycrystalline to single-crystal behavior, with improved alignment
along the [111] direction without altering the garnet structure. Magnetic
measurements show increases in saturation magnetization in B2O3-assisted fibers. Three-dimensional anisotropy energy
modeling, based on EBSD-derived Euler angles, indicates that the enhanced
crystallinity and orientation contribute to reorientation of MCA energy
distribution due to improved crystallographic alignment. Faraday rotation
measurements show that the B2O3-assisted sample
exhibits a rotation angle closer to reported values for high-quality
YIG, suggesting improved phase purity and crystallographic quality.
These findings demonstrate that B2O3-assisted
LHPG growth is a scalable and nontoxic approach to producing high-performance
YIG fibers for integrated photonic and magnetic field sensing applications.